UPDATED – February 26, 2010
Originally Published – January 25, 2010
Introduction
So many users are searching around the net these days looking for advice on how to overclock their new systems but don’t know where to start. To help everyone out, I decided a how-to guide was in order. Searching around forums can be confusing and intimidating. There are so many people willing to give advice, but who can you trust? It’s hard to know, and I’ve seen many users sent on wild goose chases because they are following advice that doesn’t solve or even address their specific problem. I’ve also seen too much trial and error overclocking. What I will attempt to do is create a very simple three step guide to “one-size-fits-all” overclocking.
If you want to continue searching out other opinions, please consider each suggestion with caution. Some will undoubtedly be great, some will not. There is one exception I would make for OC Forums- their “senior members”. These users are the ones with blue user names and blue stars. They have been designated seniors based on their knowledge, experience, credentials, and contributions to the OCF community. While not immune to error, these users generally know their stuff and can be trusted for good advice.
Credentials
So, why should you listen to me? Well I’m not the end-all-be-all of overclocking, and I still learn new things every day. There are many people around OCF whom I highly regard for their knowledge and experience. Having said that, I do have a bit experience overclocking computers successfully. I’m a member of Team IRONMODS, and if you’d like to know more about the team and our accomplishments, please visit our website. I’m also very active with the OCF benching team where I regularly participate in team events and online competitions with The Raptor Pit.
Methodology
My goal here is for this overclocking guide to be useful for anyone with a newer Intel based system, i3, i5, i7, LGA1156 or LGA1366. With the same basic principles applying to all of them, the basic process doesn’t change whether you are planning to use your system as an everyday system, gaming or if you want to push the limits for a single benchmark.
This guide is also independent of your cooling system. Whether you are using the stock Intel cooler or if you’re pushing to the extreme with liquid nitrogen, the basic steps remain the same. One thing that is far too common is errors in mounting your cooling system, specifically the application of the thermal interface material (TIM). If you don’t have much experience mounting a cooling apparatus, please refer to this excellent guide from Arctic Silver.
Determining methods for finding a stable overclock are highly controversial, and my suggestion is that we agree to disagree. Everyone has their individual definition of a stable system, but when I refer to “stable” in this guide, I am referring to the stability of your selected “stability test.” So for a power user or gamer who wants a reliable system that won’t ever crash due to an overclock pushed too far, you’d need to test with a program that will load all of the cores and threads applicable to your CPU, OCCT and Prime95 are two popular choices. For a benching team member looking to squeeze every last MHz out of their chip for a 7 second SuperPI 1M run on liquid nitrogen cooling, SuperPI 1M would be the ideal test. In my examples below, my verbiage will obviously be geared more towards those running tests like Prime95. Super PI 1M only takes a few seconds to complete, so when I say “run your stability test for five minutes” obviously you will have to tailor that instruction for your individual situation.
So with that in mind, we will attempt to isolate each portion of the system and overclock one piece at a time. This may seem time consuming at first glance, but rest assured this can potentially save you hours of troubleshooting and frustration. So go slow, and follow each step very carefully.
Disclaimer
I also need to insert a disclaimer in here somewhere: I am not responsible for any bad things that happen to you or your computer as a result of you listening to my advice, nor is overclockers.com. My goal is for this guide to be a safe overclocking guideline, but the burden for damaged hardware lies on the user performing the overclock! Overclocking can damage hardware, the new 32nm CPUs seem to be particularly fragile. Overclocking will also void your warranties.
Prerequisites
This guide is written for you if you can get around in your system’s BIOS (basic input/output system). I cannot write this guide to cover the variety of BIOS represented. If you are unfamiliar with your BIOS, search for more information regarding your specific motherboard. Also, do not be afraid to get into your BIOS and have a look around, if you are ever concerned that you may have changed a setting erroneously, you can always load defaults, and start over.
Micro-architecture
The CPU micro-architecture has taken a huge leap from the 65nm Core to the new generation 45 and 32nm technology, it has brought many changes not only to the CPU’s but also to the chipset and motherboard design and functioning. This is what make overclocking the i3/i5/i7 CPU’s so much different to their predecessor LGA 775 CPU’s.
The naming convention can be a bit confusing so let us look at the various CPU and their names:
First we have the Nehalem family which are all 45 nm CPU’s that included i7 1366 Bloomfield (i7-920 i7-975) and Lynnfield socket 1156 i5/i7 (i7-750 to i7-860). These are all quad cores with HT except for the i5 which has no HT.
Then the next family is Westmere which is essentially die shrink 32 nm CPU version of Nehalem and again you have the Clarkdale (socket 1156) in flavors of i5 and i3, both dual core processors with HT.
Gulftown which is the hex-core CPU’s and not available yet are also part of the Westmere family and features 6 physical cores with HT and will be socket 1366 only.
The above are all desktop chips, then to you get the Arrandale and Clarksfield CPU’s which are mobile processors and the Gainstown which is the server equivalent of Bloomfield.
So, to summarize, we have socket LGA 1366 and LGA1156 which are essentially the board platforms that carry certain 45 and 32 nm CPU variants. Both platforms are DDR3 where the 1156 is dual channel only.
Intel Core i3, i5, and i7 CPU’s
The following are the different CPU’s available today on the market, except for the Gulftown hex cores which will be available late 3rd quarter of 2009.
Core i3 (Clarkdale – i3 530, 540)
The least expensive and least powerful choice are the Core i3 chips. These are currently limited to two physical cores with both the i3 530/540 models supporting Intel® Hyper-Threading Technology. At this time, all i3 CPUs have two pieces of silicon (or dies) in the CPU. One contains the actual processing cores and all of the L1, L2, and L3 caches. The second die contains a GPU (graphic processing unit) which is capable of outputting video without the use of a dedicated video card when used with an H55 or H57 based motherboard. This second die also contains the PCIe controller and the dual channel IMC (Integrated Memory Controller). The first die is manufactured on a 32nm process, the second die is manufactured on a 45nm process. The two die are linked with the Intel QPI (Quick Path Interface). All i3 CPUs work only on LGA1156 based motherboards.
This is all very important to understand when attempting to overclock one of these CPUs, because you are actually in a constant juggle with overclocking both dies. Why? Because both dies derive their speed from the bclock (base clock) frequency. Please understand that these new 32nm CPUs are more sensitive to high voltages, and have been known to fail even when core temperatures are well within “safe” limits. Another major issue many users have been running into with overclocking these Clarkdale based CPUs is the IMC. It is not nearly as powerful as the Lynnfield based CPUs, and many users are forced to run at slower memory speeds and timings to get stable.
Core i5 (Clarkdale - i5 650, 660, 661, 670)
Dual core i5 CPUs (Clarkdale) are identical to the i3 CPUs, but also include Intel® Turbo Boost Technology. All i5 CPUs work only in LGA1156 based motherboards.
Core i5 (Lynnfield – 750)
Quad core i5 CPUs (Lynnfield) are identical to the low end i7 CPUs, the only exceptions being their lack of Intel® Hyper-Threading Technology, Intel® Virtualization Technology for Directed I/O (Intel® VT-d) and Intel® Trusted Execution Technology (Intel® TXT). All i5 CPUs work only in LGA1156 based motherboards.
Core i7 (Lynnfield – i7 860, 870)
The low end Core i7 (Lynnfield) are quad core CPUs made for LGA1156 based motherboards. These CPUs are manufactured on the 45nm process. They have dual channel IMCs and PCIe controllers built into the CPU die. All i7 CPUs include Intel® Hyper-Threading Technology and Intel® Turbo Boost Technology. Lynnfield based CPUs are unique in that they do not have a QPI. Because the PCIe and memory controllers are both integrated on the CPU die, there is no need for the QPI. They are known to have incredible IMCs and are capable of sustaining extreme memory bandwidth.
Core i7 (Bloomfield – i7 920, 940, 960, 965/975)
The mid range Core i7 (Nehalem) are quad core CPUs made for LGA1366 based motherboards. These CPUs are manufactured on the 45nm process. They have triple-channel IMCs built into the CPU die. The PCIe controller is not part of the CPU, but is built into the chipset (on the motherboard), the CPU and chipset are linked with a QPI. All i7 CPUs include Intel® Hyper-Threading Technology and Intel® Turbo Boost Technology.
Core i7 (Gulftown – i7 980x)
The high end Core i7 (Gulftown) are hex (six) core CPUs made for LGA1366 based motherboards. These CPUs are manufactured on the 32nm process. They have triple channel IMCs built into the CPU die. The PCIe controller is not part of the CPU, but is built into the chipset (on the motherboard), the CPU and chipset are linked with a QPI. All i7 CPUs include Intel® Hyper-Threading Technology and Intel® Turbo Boost Technology. Please understand that these new 32nm CPUs are more sensitive to high voltages, and have been known to fail even when core temperatures are well within “safe” limits.
Setup
Before we do anything, please start by going into your system’s BIOS, and load defaults, then save and exit. Your machine will restart with default BIOS values. Enter the BIOS again and disable all power saving features. These include, but are not limited to; EIST, C1E, and all other C-states. All other settings you can leave on auto for now. Although I would also recommend turning off any start-up slash screens, so that you can view your system’s post behavior. Also, feel free to disable any “integrated peripherals” that will not be used (i.e. NICs, extra PATA/SATA controllers, legacy devices, etc).
If your motherboard fails to post after changing certain settings, you will have to locate and reset the CMOS. Resetting the CMOS restores the BIOS to its factory settings and is a “hard” reset of these settings. Become familiar with where the CMOS jumper or button is, you may need to use it a lot. Most of the time, a jumper is located near the battery on the motherboard. Most newer motherboards have a button in the same location and many may also have a button on the rear input/output panel for easy access when your motherboard is installed in a case. If you need to reset the CMOS, please power off the system by flipping the switch on your power supply, or unplugging it completely for 10 sec, then activate the CMOS reset jumper/button for 10 sec.
Understanding CPU frequency
Before we go into how we overclock these CPU’s let us look at what determines how fast your CPU will run. The following simple equation determines the clock speed of the CPU’s cores:
CPU Frequency = Base Clocks x Multiplier.
This is a biggest change from the old LGA 775 where FSB and multiplier determined the CPU speed. The base clock is similar to the FSB but also has some key differences. The base clock, also commonly spelled bclocks or bclk in forms, is the foundation around all the other frequencies discussed below.
The CPU speed of the new generation is not the only factor that determines how fast your PC will run, we have a few more definitions such as:
QPI Frequency – QPI or Quick Path interconnect is the Intel communication path upgrade from the older chipset and front side bus (FSB) communication path, so instead of the CPU communicating with the memory via the LGA 775 Northbridge, there is now a direct link (QPI) that increases efficiency. QPI speeds are a function of base clocks, so as you increase your base clock your QPI speed will also increase, yielding an increase in not only communications speeds but also bandwidth, which leads to an increase in PC performance.
Uncore frequency – This sets the frequency of the on-die memory controller and the L3 cache. Like CPU clock speed, dram speed, and QPI frequency, uncore is a multiple of Bclk. Uncore can be set independently of those other frequencies, subject to certain stability limitations. The uncore must be at least 2:1 of the DRAM speed otherwise you will not get a stable overclock, in fact your PC will not even boot if the ratio is not honored. Increasing the uncore:dram ratio above 2:1 yields significant performance gains. However, when the ratio reaches 3:1 it is not possible to maintain full stability.
Multiplier and Turbo – As mentioned above, the multiplier is the second factor in how CPU core speed is determined. Now, not all CPU’s have the same multiplier, it is dependent on where the CPU is positioned in the price/performance curve of Intel’s range of CPUs. Most of these come with a Turbo multiplier which is available if you enable the Speedstep option under the CPU settings. Care should be taken when using the turbo as you may not be able to see the resultant frequency in the BIOS. For instance, if your default multiplier of your CPU is 20 (i7-920) and you set your baseclock to 200 and you boot up with turbo enabled, you will leave the bios at 20 x 200 = 4 GHz, as soon as you enter your Operating system your turbo kicks in so you end up with 21 x 200 = 4.2 GHz. Now if you also have C-State enabled, one CPU core will actually have access to a 22 multiplier which enable that core to run at 22 x 200 = 4.4 GHz. You set your voltages expecting to run at 4 GHz and you cannot understand why you get a BSOD when you enter Windows, well, that is the reason, so take care when using turbo and C-State and adjust voltage to accommodate for the higher multipliers.
Important Voltages when Overclocking
There a few important voltages which you will need to manipulate while overclocking, below are the main ones. Every motherboard Bios differ but all of them have the voltages as set out below.
- V-Core – Directly related to the CPU frequency. As you increase the CPU frequency you would need incrementally increase the v-core as well.
- QPI voltage/CPU Vtt – Increase in this voltage is necessary from the default as you increase your RAM speed, tighten the timings or increase QPI frequency. It also helps to stabilize your overclock at higher base clocks.
- VDIMM/DRAM – This is directly related to your RAM memory modules and increase will assist in stabilizing increase in Ram speeds. Care should be taken not to increase this voltage more that 0.5 volts above your Vtt as you could cause permanent damage to your CPU.
- IOH Core Voltage- This voltage aids when increasing base clocks above say 200. In most cases leaving it at auto works best.
- ICH Core Voltage- This voltage feeds the chip that regulates the communication from the peripherals to the CPU via the DMI. It is best to set this at auto.
Now that we have covered all the basics let us jump to what this article is all about…overclocking
Step 1) Maximize Bclock Frequency
Isolate the bclock from the CPU
First you need to isolate the bclock and find its stable limit with your chosen cooling. In order to isolate the bclock from the other components, the first thing you need to do is manually force a low multiplier for the CPU. For example; at stock speed, an i5 750 runs on a 133MHz bclock and a x20 multiplier which results in its stock speed of 2660MHz (133×20). Raising the bclock to 200 with the stock x20 multi would result in 4000MHz for the CPU, which you’re not quite ready for yet. If you are shooting for a 200MHz bclock, then a safe choice for now might be a x12 multi, which would result in a CPU speed of 2400MHz if you were successful in reaching your 200MHz target bclock. Doing this isolates the CPU from the bclock so you can focus on only bclock overclocking in this step. In some situations, x12 may not work, this is just an example though, so don’t be afraid to try other low multipliers if x12 doesn’t work.
Isolate the bclock from the memory
The fastest rated speed for memory on P55 with an i5 750 (for example) is DDR3-1333, which is a clock speed of 667MHz (dual data rate “DDR” doubles the bandwidth to 1333-like speed). Just like the CPU, the memory receives its clock from the bclock via a multiplier, in this case x5 (133×5=667). This is most often expressed in the BIOS as “2:10″. If you were to overclock the bclock to 200MHz as described before, your memory would be running at 1000MHz (DDR3-2000), and beyond the specs of all but the most extreme memory. To isolate the memory from the bclock, lower the memory multiplier to the lowest setting available, most likely 2:6. If you were to reach your goal of 200MHz bclcok frequency, your memory would only be at 600MHz (DDR3-1200) and well within the capability of all but the worst DDR3 on the market.
Isolate the bclock from the iGPU (Clarkdale only)
Clarkdale CPUs include an iGPU (integrated Graphics Processing Unit). If you are using an H55 or H57 based motherboard and the iGPU is enabled, please pay close attention to this section. Some early BIOS versions did not allow for iGPU clock speed adjustment, if you do not have this option in your BIOS, please update your BIOS to the most recent version. This platform is still very new and immature, so this information may only be relevant for a short time. However, at this current time, it appears as though the iGPU frequency setting in the BIOS is based on the default bclock frequency. This means that an iGPU frequency that is set at 900MHz in the BIOS, will only actually be 900MHz if the bclock frequency is set to 133MHz, if the bclock frequency was raised by 25% to 166MHz, the actual iGPU frequency would also go up by 25% or 1125MHz. This is a relatively simple concept to understand, except that YOU have to do the calculation, because the BIOS only reports the set frequency, not the actual frequency. What makes things worse at this time is that there is no software monitoring utility that is capable of reading the actual iGPU frequency.
For now, it’s only important to isolate it as a variable from our overclocking process. So, assuming your goal is 200MHz bclock frequency, which is a 50% overclock of the bclock frequency, you need to lower the set iGPU frequency to prevent its overclock during this process. If the stock iGPU clock speed is 900MHz and we were to overclock it 50%, that would yield a 1350MHz actual iGPU frequency. To bring 1350MHz back down to 900MHz we would need to reduce it by 33%. So reduce the set iGPU frequency by 33% to 600MHz, with our stock bclock frequency, the actual iGPU frequency would also be 600MHz. However, if you successfully reach your target 50% increase in bclock, your set iGPU frequency will yield an actual iGPU frequency of 900MHz, which is the iGPU’s stock speed.
Bclock voltages
For this step, there are only two voltages you should play with; VTT, and IOH. IOH is easy, if you are running a single PCIe card (graphics card), give the IOH 1.3V, if you are running more than one PCIe graphics card, give it 1.35V. VTT is the crucial voltage adjustment for achieving high bclock stability, which is also known as “CPU VTT”, “QPI/VTT”, or “QPI/DRAM”. This is the voltage that is fed to the IMC (Integrated Memory Controller), and also has a major impact in overclocking the bclock. CPU VTT is the crucial voltage adjustment for achieving high bclock stability. Stock values differ depending on platform and CPU, but as a rule of thumb LGA1366 likes a lot, P55 doesn’t need as much.
So, are you ready to start overclocking? After entering your BIOS and lowering the CPU & MEM multipliers, go to the voltages section and raise your IOH to 1.3-1.35V and your CPU VTT to +0.2V. Then restart your machine and go back into the BIOS, if your system fails to post and return to the BIOS, please re-read the last paragraph in the “prerequisites” section above, and start over. If you still cannot get past this step, post in the forums for some specific help.
After you’ve restarted your system with your manually configured voltages and returned to the BIOS, I always recommend going to the temp/voltage monitoring section and checking the CPU temp. If the temperature seems too high for your cooling, then shut the system down and double check that your cooling system is properly mounted, and making good contact. Moving on, almost all systems should be able to achieve 150MHz bclock stability with stock voltages, so go to the bclock adjustment and change it from 133MHz to 150MHz. Then save and exit and allow the system to reboot. This time, allow the system to boot fully into the operating system.
Testing for highest stable bclock frequency
Once the operating system has fully loaded, start up RealTemp. RealTemp should always be running while checking for stability of an overclocked system to ensure you do not overheat your CPU. RealTemp shows your CPU’s core temperatures real-time, as well as the distance to TJ Max, my advice is to never exceed TJ Max. Now start up CPU-Z, this will allow you to ensure that your overclocked settings have been properly applied, and that you are running at your desired speed. Check both the CPU tab for the expected CPU frequency (should be 1800MHz at this point), and check the memory tab to ensure your memory is running at the proper speed (CPU-Z will show the frequency of the memory, not the DDR3 speed, it should be 450MHz at this point). Now start up your selected test program, for example OCCT or Prime95. Run the test for just a short amount of time, five minutes should be plenty. Then reboot the system and return to the BIOS.
If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again. If the test failed, raise the CPU VTT voltage by a small increment, reboot into your OS and run the test again. You should be able to see where this is going, continue to raise bclock or CPU VTT voltage with a short test after each change, until you meet one of the following criteria:
- You reach your desired bclock and successfully pass your stability test.
- You reach your maximum safe CPU VTT voltage.
- Raising the CPU VTT does not allow for additional stability.
* Note – there is a phenomena known as “bclock holes,” which seem to be less common now, but may still create confusion and frustration during this process. But if you appear to have found your limit at a much lower speed than anticipated, please consider trying a step or two higher before continuing on. A bclock hole causes system instability a particular bclock values, and going past them may allow you to regain stability.
Maximum safe CPU VTT
What is the maximum safe CPU VTT voltage? Depends on a lot of things, but I feel like these are some basic conservative guidelines. If you’re running the stock Intel heatsink and fan, I would not advise more than +0.2V, if you are running a high end air cooler I would not advise more than +0.3V on LGA1156 platforms, and no more than +0.4V on LGA1366 systems. If you are running a high end custom water loop add another 0.05V to those values, and if you are using extreme forms of cooling then use whatever works best. I’ve used up to 1.70V on an i7 920, and up to 1.55V with my i5 750 with extreme cooling.
Fine tuning
After you have met one of the criteria above, you should have a rough idea of your bclock limit, now it’s time to get a little more fine tuned. Next, instead of 10MHz bclock changes, shift to 2MHz changes. Then repeat the steps above and search for one of the three criteria again. Also, ensure you check my note about “bclock holes” above, the same concept can be applied to this fine tuning step as well.
After you have found your highest stable speed to within 2MHz accuracy, lower the bclock by 2MHz and run your test again. This time let it run for a full hour (for those of you testing with Super PI or similar, adjust for your situation). If it passes the test - Congratulations! – you have found your highest stable bclock frequency.
Step 2) Optimize Memory Frequency
DDR3 Basics
The next step is to find the limit of your memory. To do this, first you need to look at the memory’s ratings. DDR3 does not typically have a lot of overclocking headroom, so it’s important to start with stock settings. In this example I will use some basic Crucial Ballistix PC3-12800 for my explanations. This memory is rated for DDR3-1600 (800MHz) 8-8-8 24 1T with 1.65V. Enter the BIOS and adjust your memory timings according to the manufactures rating, in this case 8-8-8 24 1T. Now, consider your maximum/desired bclock frequency, 200MHz for example. This memory has a stock speed of 800MHz, so a 2:8 ratio with a bclock of 200MHz would put us right at that stock speed of 800MHz. You could set it and leave it there, but let’s say your maximum/desired bclock is not 200MHz. For example, if you are actually trying to reach 210MHz. If that were the case, the resulting memory frequency would be 840MHz (DDR3-1680). So, similar to finding bclock stability above, we need to work our way up to the desired speed testing along the way. There is an exception to this section, and that is with Clarkdale base Core i3 and Core i5 CPUs. They tend to have a very weak IMC, and are often times not capable of running memory even at their stock speed. If you have a Clarkdale based CPU, you may have to sacrifice memory speed to attain a good CPU overclock.
Testing for highest stable memory frequency
Theoretically we should be able to run for at least an hour with the bclock at 200MHz and the memory multi at 2:8– why? Because we already found out that this bclock speed is 1 hour stable, and we are not overclocking the memory yet.
However, the integrated memory controller (IMC) is powered by the CPU VTT voltage. So under some circumstances, especially with the newer 32nm CPUs, you may not be stable with your memory even at stock speeds due to the overclock imposed on the IMC. This is particularly true if you are running 4 DIMMS (P55/H55/H57), 6 DIMMS (X58), or 4GB DIMMS (P55/H55/H57/X58). If this is the case keep the memory at stock speed, or even try dropping the memory clock multiplier to run at less than stock speed, and increase the CPU VTT voltage until you gain stability. The newer 32nm CPUs seem to have particularly weak IMCs, and often will not run at the higher multipliers even if your memory is perfectly capable.
For testing memory, it is important that you take a break from whatever stability test you’ve been running, and use memtest86+ instead. The easiest way is to download the .iso and burn it to disc. Then configure your BIOS to load from your optical drive before the hard disk drive. When you boot the system with the disc inserted, memtest86+ should start automatically, and immediately begin testing your memory.
But, our goal is to reach 210MHz bclock, which will result in 840MHz memory frequency. In the BIOS, set your bclock to 202MHz, and your memory multi to 2:8, save settings and exit. Allow memtest86+ to load and complete one entire loop. A single loop can vary in length, and can take quite a while if you have a large amount of memory installed. If the test ran without error, press Ctrl-Alt-Delete and enter your BIOS. Raise the bclock by 2MHz and then save and exit. If the test failed, raise the memory voltage by a smallest increment possible, and run the test again. You should be able to see where this is going. Continue to raise bclock or memory voltage until you meet one of the following criteria:
- You reach your desired bclock and successfully pass a single loop of memtest86+.
- You reach your maximum safe memory voltage.
- Raising the memory voltage does not allow for additional stability.
Maximum safe memory voltage
What is the maximum safe memory voltage??? This is determined by two things: first, NEVER INCREASE THE MEMORY VOLTAGE MORE THAN +0.5V OF THE CPU VTT VALUE, second, how much do you enjoy killing your memory? Throughout recent history, memory is probably the easiest component to damage with extra voltage. While there are exceptions, most newer DDR3 memory modules do not need very much voltage to reach their practical limits.
Once you have satisfied one of the three criteria above, drop the bclock down 2MHz from your last stable setting, and see if memtest86+ will run through 2 or 3 loops without error. If you wish to try to push your memory even further at this point, there is one more thing to try, and that is another bump in CPU VTT voltage. This will possibly boost the capabilities of the IMC and give you a little more room to overclock the memory. Otherwise - Congratulations! - you now have a relatively stable bclock frequency and memory frequency.
Step 3) Stabilize CPU Frequency
Almost there
The last step in this guide is often the first step for users who run into problems and then troubleshoot for days afterward. Leaving it to the last step makes the task much simpler. You now have the following settings locked in; CPU VTT, IOH voltage, memory voltage, memory multiplier, and memory timings. That means when we are looking for our highest CPU frequency, there are only two variables we need to play with: bclock and CPU voltage.
Right now your CPU multiplier should be very low, and your bclock should be quite high. If we move the CPU multiplier up right now, we would undoubtedly become very unstable, and unlikely to post. The idea here is that if your bclock and memory are stable with the current settings, shifting the bclock down should not cause any instability. So, change you bclock to 140MHz, and switch your CPU multi up to its maximum. In our example i5 750, the normal maximum would be x20. Intel’s Turbo feature allows for extra multipliers, and some BIOS will even allow for the higher multipliers to be forced. It will not hurt to use this feature if you desire. So with my example of the i5 750, with some BIOS, I would be able to lock in a multi of x21.
“Load-line calibration”
This actually goes by a few different names, but they are all meant as a means to reduce or prevent v-droop. Most overclockers would advise you to enable this feature; I would only recommend it if you understand what it does. It does typically allow for measurably higher overclocking, but at the cost of violating Intel’s design specs, and putting more stress on the CPU. However, overclocking in its essence violates Intel’s design specs, so you’re not breaking any new ground with this feature. I do not enable load-line calibration on my daily/gaming system. But I always use it when I am trying to fine the absolute limit. For more insight on the matter, refer to this excellent explanation at anandtech.com.
CPU Voltage
That brings us to the first thing that most users want to play with after powering up their new system for the first time: CPU voltage, aka “vcore”. As you can see, this is actually one of the last things you should be changing. I would recommend starting at a nice and easy 1.3V. Surprisingly enough, many users are able to achieve very good overclocks with this modest amount of CPU voltage.
Testing for your highest stable CPU frequency
Once the operating system has fully loaded, start up RealTemp. Now start up CPU-Z and verify that your overclocked settings have been properly applied, and that you are running at your desired CPU, bclock, and memory frequencies. Now start up you selected test program, for example OCCT or Prime95. Run the test for five minutes. Then reboot and go back into the BIOS.
If the test ran without error, the raise the bclock by 10MHz, reboot into your OS and run the test again. If the test failed, raise the CPU voltage by 0.025V, reboot into your OS and run the test again. Continue to raise bclock or CPU voltage until you meet one of the following criteria:
- You reach your desired bclock and successfully pass your test.
- You reach your maximum safe CPU voltage.
- Raising the CPU voltage does not allow for additional stability.
Maximum safe CPU voltage
For there is no maximum “safe” CPU voltage in my book. My recommendation is to determine your maximum safe voltage based on your temperatures while running your stability test. With stock air cooling this could be as low as 1.3V on some i7 CPUs while running OCCT. Or it could be as high as 2.2V when attempting Super PI 1M with an i5 670 on liquid nitrogen. Personally, I don’t like to see my load temperatures exceed 90C on air or water cooling, but it’s really up to you.
Is it stable?
So, once you find your highest CPU frequency by meeting one of the criteria above, lower the bclock by 5MHz, and run your selected stability test until you are satisfied. If you are looking for a stable system as a power user or gamer, OCCT or Prime95 for six hours is more than sufficient in my testing, but you may run longer if you desire. But for a true test of stability, I always like to play Crysis while encoding a Blu-Ray movie into an mpeg4 format.
Cooling
Cooling your CPU, RAM and other heat generating components are key to the success and the level of how high you overclock your CPU. Do not expect to reach the same level of CPU speeds on air or water cooling than your fellow bencher who is using liquid nitrogen.
Cooling not only plays a huge roll in reducing temperatures but is also determine how much voltages you can feed to your CPU before you damage or even kill it, especially with the 32nm Westmere CPU’s who are much more sensitive to voltages. Electronic components behave differently under extreme cooling than under conventional cooling.
Use voltages in moderation and rather be safe than sorry, especially if you cool with conventional cooling such as air or water.
Final Words
Well, that about wraps it up. Believe me, there is so much more to overclocking. There are SO MANY settings you can continue to fiddle with, but this guide should get you 95% of the way in 5% off the time. If you enjoy overclocking you system, I highly recommend joining one of the teams at OCForums. If you like to push your system and you like to get competitive, look into joining one of our great folding teams, or the OCForums Benchmarking Team. You’ll learn a lot and have a blast!
Please feel free to comment, and post any questions you have in the thread linked below where the great OCF community will help you out with any problems you may encounter!
Thanks to Brolloks and others for their help with this guide.
Related posts:
- A Detailed Step by Step Guide to Folding@Home Under Linux
- Intel Core i7 Overclocking
- Dual Core Netbook – One Step Closer
- Step-by-Step: How to Build a Cheap and Quiet AMD Dually
- AMD Core Unlocking With MSI. How Much Easier Can It Get?!
Tags: easy, extreme, guide, how to overclock, i3, i5, i7, newbie, noob, OC, OCing, overclocking, pll, Reference, vcore, vtt, walk through
01-25-10 12:25 PM
01-25-10 12:35 PM
01-25-10 12:45 PM
01-25-10 01:27 PM
01-25-10 04:26 PM
01-25-10 08:11 PM
STICKY
01-25-10 08:56 PM
01-25-10 08:57 PM
Thank you for writing this. Now I have confidence to begin overclocking having some knowledge of why a value should be tweaked or not.
After reading that, I noticed it was posted today! (1/25/2010), and I immediately signed up to this forum..
01-25-10 09:13 PM
01-26-10 09:16 AM
01-26-10 09:55 AM
01-26-10 10:08 AM
01-26-10 11:48 AM
01-26-10 11:59 AM
+1 for sticky
01-26-10 04:32 PM
01-26-10 07:43 PM
01-26-10 10:52 PM
01-26-10 11:37 PM
01-27-10 03:49 AM
No...as stated in the guide, these should be left on "auto"...Raising the PCH is a bad idea, and I've heard can burn HW pretty quick...I have not found it to help an OC at all. The PLL can even be lowered a bit
01-27-10 11:05 AM
01-27-10 03:30 PM
01-27-10 05:14 PM
01-28-10 01:46 AM
01-28-10 02:50 AM
01-28-10 08:51 AM
01-28-10 11:12 AM
What you propably have heard that you could lower your v-core if you increase your Vtt slightly to stabilize your OC, but is does not happen automatically.
01-28-10 01:24 PM
Whoa there. If somone is running ACHI and set's BIOS defaults won't it default to IDE?
Then they get Error Code
"STOP 0x0000007B INACCESSABLE_BOOT_DEVICE"
http://support.microsoft.com/kb/922976
I know it's easy to go back into the BIOS and change it back to ACHI, but telling novice not to write down the setting BEFORE they change the BIOS is asking for trouble.
Of course if they never changed it to ACHI it's one of the 1st things they should do before the OS install.
Otherwise loved the writeup.
DM
01-28-10 01:34 PM
I guarantee, at some point and some overclock, they're going to need to reset CMOS. Doing so will remove any ACHI setting. They'll need to know how to recover from that just as much as they would from setting defaults.
You are correct though, it will default to IDE.
Oh, and welcome to OCF!
01-28-10 02:40 PM
Telling them to start off with changing to "default" is just asking for trouble. Most of us don't need the guide. But this is for the person who is not experienced. That person will do this.
When I build a system the 1st thing I do is reset to Default, then Kill the Stupid Splash Screen on the BIOS, then the ACHI Mode if Sata.
I have seen too many people change the BIOS settings and not have a CLUE. A+ Classes, MCSE Classes, Network Classes etc.
01-28-10 03:35 PM
Anyhow, thanks for the feedback, I'll be working on a follow up shortly to address some of the suggestions I've recieved, and I'll definitely consider adding a note on this
01-28-10 08:25 PM
Oops
Snap, Crackle Pop. It don't work anymore. Give me another one please.
(Novell Class where they took everything apart for Practice, they just could not put them back together and functional).
One other thing to consider. When I build I go into BIOS and check the temps. Good way to make sure you have those STUPID Push Pins on right! Before I load OS or try to OC it. So many don't bother to check until they ask "Why is it running so HOT or keeps shutting down".
Also put in there something about "Never Flashing BIOS on OC System" unless you play Russian Roulette with S&W Model 410. Good way to make a brick out of running system.
Dm
01-28-10 08:35 PM
01-29-10 09:45 AM
Thanks
01-31-10 01:19 AM
02-01-10 09:08 PM
This is exactly what I needed. I've been out of the seen for so long that all these new terms in the bios totally threw me off!
Thanks!
02-03-10 01:56 AM
02-09-10 02:36 PM
Just a few examples - please don't get hung up on just these:
- What the heck is IOH? There's no such thing in my EVGA E657 BIOS.
- Vcore is much more critical than VTT on P55. It really is! I run VTT at Auto but had to bump Vcore up significantly (but reasonably) to reach 4.2GHz on a Core i7 860.
- What about the 1.65V hard-limit for safe RAM voltage on P55? Your guide only says VTT for i5 can get as high as 1.55V but that RAM voltage can go up to 0.5V higher; if people take that to mean 2.05V for RAM on P55 (NO!) then they'll fry their hardware.
02-09-10 10:43 PM
Most of what is in this guide is applicable to the P55 platform, remember that the micro-architecture of the CPU's that go into the X58 boards are the same as those that go into the P55 boards, they all belong to the Nehalem (45nm) or Westmere (32nm die shrink of Nehalem) family. Bloomfield is X58 based and Lynnfield is P55 based and both is 45nm micro-architecture, they all have the memory controllers on the CPU die. The P55 CPU's also have base clocks and multis which determine the CPU speeds. Both have uncore and QPI speeds that are key to CPU performance.
Vtt, or also known as QPI voltage, is just as important on the P55 CPU's as it feeds the IMC (Internal memory controller) and aids in memory OC as well as higher base clock stability. Vtt should also be used with more care on the Westmere 32nm chips whereas the 45nm Nehalem CPU's can tolerate much more.
The 1.65 VDIMM limit is a myth really and has been disproved thousands of time over, as long as you keep your RAM voltage and VTT within 0.5v you will be good.
Please read the guide, use what works for you and adjust, that is how you learn, that is how we all learned, from the masters, then a few like Miahallen became a master himself
02-20-10 07:36 PM
02-20-10 09:17 PM
02-21-10 08:43 AM
02-21-10 08:59 PM
http://img704.imageshack.us/img704/6...bclk138vtt.png
http://img693.imageshack.us/img693/4...bclk136vtt.png
02-25-10 02:21 PM
I was able to get 4Ghz (8hrs stable) without ht, and only 3.8ghz with ht only somewhat stable prior to this. Using this guide as a reference I'm now working towards 4.3Ghz HT stable. Breaking it up into sections like that is the key, you cant change a ton of settings at once because then you dont know why its failing.
Breaking it into sections allows for much easier trouble shooting. Keep up the good work man
02-26-10 02:28 PM
Update has been published folks...catch it here!
02-27-10 02:49 AM
One piece of feedback that I wanted to leave is that as an owner of an i5-750 running on a GIGABYTE GA-P55M-UD2 I found some of the variables mentioned in the guide to be missing or new ones to be present. If you're completely green like I am, it's be very helpful to know how those additional (or missing) variables relate to what's in the guide. Here's a couple of points that were unclear to me:
- The "Bclock voltages" section talk about an IOH voltage. On my p55 gigabyte there's no such thing, instead I have a CPU Vcore, a Dynamic VCore (DVID) and a QPI/VTT Voltage. The Vcore is mentioned at the end of the guide in step 3. Given that IOH appears not to exist in P55, do I just ignore the suggestion to raise it to 1.3-1.35?
- In the same section, and in the rest of the guide, you measure tweaks to the VTT in terms of +0.xV (where x is a number). What does that actually mean? Are you saying we should take the default value of the BIOS and increase that by +0.xV? I guess the confusing part is that in my menu there's the DVID variable which actually does have + and - 0.xV settings, so to me it's not clear whether you're asking to keep the VTT default and tweak the DVID, or if I should ignore the DVID and only increase the VTT.
Thanks!
02-27-10 11:37 AM
http://img704.imageshack.us/img704/6...bclk138vtt.png
http://img693.imageshack.us/img693/4...bclk136vtt.png
I was able to get 4Ghz (8hrs stable) without ht, and only 3.8ghz with ht only somewhat stable prior to this. Using this guide as a reference I'm now working towards 4.3Ghz HT stable. Breaking it up into sections like that is the key, you cant change a ton of settings at once because then you dont know why its failing.
Breaking it into sections allows for much easier trouble shooting. Keep up the good work man
One piece of feedback that I wanted to leave is that as an owner of an i5-750 running on a GIGABYTE GA-P55M-UD2 I found some of the variables mentioned in the guide to be missing or new ones to be present. If you're completely green like I am, it's be very helpful to know how those additional (or missing) variables relate to what's in the guide. Here's a couple of points that were unclear to me:
- The "Bclock voltages" section talk about an IOH voltage. On my p55 gigabyte there's no such thing, instead I have a CPU Vcore, a Dynamic VCore (DVID) and a QPI/VTT Voltage. The Vcore is mentioned at the end of the guide in step 3. Given that IOH appears not to exist in P55, do I just ignore the suggestion to raise it to 1.3-1.35?
- In the same section, and in the rest of the guide, you measure tweaks to the VTT in terms of +0.xV (where x is a number). What does that actually mean? Are you saying we should take the default value of the BIOS and increase that by +0.xV? I guess the confusing part is that in my menu there's the DVID variable which actually does have + and - 0.xV settings, so to me it's not clear whether you're asking to keep the VTT default and tweak the DVID, or if I should ignore the DVID and only increase the VTT.
Thanks!
- IOH
This does not apply to all boards, as many lower end boards do not support extensive OCing features in the BIOS. Since you do not have the ability to tweak IOH, just pass that section. (the difference will be minor anyway, VTT voltage adjustments are the main factor in bclock OCing).
- VTT and DVID
VTT adjustments are made over the default value which is different for different platforms. That is why I refer to VTT in +0.xV adjustments. DVID is a very cool feature, but my guide is writen to no use it, please disable it! If you want to explore DVID possibilities, please start a thread to discuss it (if I don't chime in, PM me and give me a link to your thread so I can help out)
OCing can get very complex, so I thried to make this guide as green friendly as possible, while still empowerin users with the basic knowledge to understand what they are doing. It's a lot to swallow in one sitting, so take your time, and don't rush
Update has been published folks...catch it here!
02-27-10 12:53 PM
02-27-10 06:52 PM
02-27-10 09:08 PM
02-28-10 03:20 PM
Learning all I can
02-28-10 04:48 PM
03-01-10 09:59 AM
Quad core i5 CPUs (Lynnfield) are identical to the low end i7 CPUs, the only exception being the lack of Intel Hyper-Threading Technology. All i5 CPUs work only in LGA1156 based motherboards.
I5 750 being the only quad core out right now, you can add to that blanket statement "and vt-d, which allows virtual machines direct access to the hardware."
See the following:
http://en.wikipedia.org/wiki/X86_virtualization#IOMMU
It's basically the stuff required for using real 3D hardware in VM's. I say give it 2 more years and somebody will come up with some type of shell operating system that lats us run Linux and Windows in parallel. A super lightweight and flexible hyper-visor...
03-01-10 10:11 AM
Quad core i5 CPUs (Lynnfield) are identical to the low end i7 CPUs, the only exception being the lack of Intel Hyper-Threading Technology. All i5 CPUs work only in LGA1156 based motherboards.
I5 750 being the only quad core out right now, you can add to that blanket statement "and vt-d, which allows virtual machines direct access to the hardware."
See the following:
http://en.wikipedia.org/wiki/X86_virtualization#IOMMU
It's basically the stuff required for using real 3D hardware in VM's. I say give it 2 more years and somebody will come up with some type of shell operating system that lats us run Linux and Windows in parallel. A super lightweight and flexible hyper-visor...
03-01-10 10:28 AM
03-01-10 11:55 AM
03-01-10 12:16 PM
03-01-10 12:23 PM
With appropriate linkage of course.
03-01-10 03:10 PM
03-01-10 09:27 PM
- What is usually the cause for the inability of the computer to post? Low VCore or VTT? It'd be good to know in case you made a tweak and all of a sudden the box won't boot and you have no idea what can be improved about the previous set of settings.
- What do you do in case there's no CMOS reset button? Pull the battery out?
- Sometimes a certain set of settings works fine and resets fine, and is perfectly stable throughout tests, but then it might not post the next time you turn on the machine. Why?
03-01-10 09:27 PM
If anyones interested ive worked out an equation to find out what your graphics clock should be set to to keep it from overclocking with your base clock.
a=Overclocked Base Clock
b=Default Base Clock
c=Default Graphics Clock
x=New Graphics Clock
x=c/(a/b)
for example say you have an i3 with its gfx clock at 733, your default bClock is 133 and its overclocked to 210
a/b = 210/133 = 1.5789...
c/1.5789... = 733/1.5789 = 464
So you would set you gfxClock to 464
Hope thats useful for someone
03-01-10 09:50 PM
- What is usually the cause for the inability of the computer to post? Low VCore or VTT? It'd be good to know in case you made a tweak and all of a sudden the box won't boot and you have no idea what can be improved about the previous set of settings.
Because of the number of variables it is recommended to start OCing slowly as the guide decribes, increments rather than large changes which normally results in no post and failute to boot. I always save my last successfull OC so I can restore it even if I have to reset the CMOS, it acts as your baseline or fallback in case something goes wrong.
If you set your QPI, uncore or RAM speeds too high it almost always result in a no-post an your system will not start up, so be carefull when you OC those, again, small incremental OC steps work.
If you are end up in Windows and get BSOD under stress testing it is either one of two most of the times, low Vtt or low V-core. Once again I have found that Vtt is 3 out of 5 times the culprit. If you make it pass booting but get BSOD as you enter Windows then it is most probably lack of v-core
- What do you do in case there's no CMOS reset button? Pull the battery out? All boards have CMOS reset options, either in the form of a push button or a jumper, consult your board manual to see what applies to your particular motherboard, If all else fals pulling the battery will certainly reset the CMOS and set bios to default settings.
- Sometimes a certain set of settings works fine and resets fine, and is perfectly stable throughout tests, but then it might not post the next time you turn on the machine. Why? Albeit not very often I have come across what you are describing, what I have found is more often the board is not fully compatible with the RAM you using or the bios is unstable, in such a case try updating the bios or as a last resort RMA the board, as I said it does not happen much but it has a change to stock out its head now and then.
03-01-10 10:10 PM
- start to boot, but then audibly restart before the post screen. Sometimes 1-3 times, then eventually it would post and work fine afterwards.
- not post at all, which is what I ran into.
The reason why I don't think the RAM is the issue is because this no-post issue was never there when the system was at stock values, so I'm trying to determine what exactly was fubarred.
03-01-10 10:22 PM
03-01-10 10:42 PM
2 x G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
Intel Core i5-750 Lynnfield 2.66GHz
GIGABYTE GA-P55M-UD2 LGA 1156 Intel P55 Micro ATX Intel Motherboard
What's ironic is that I picked those sticks specifically because they were supposedly compatible with that board.
03-01-10 11:06 PM
Not that the UD2 is a bad board but it has limitations to OC.
03-02-10 12:55 AM
Not that the UD2 is a bad board but it has limitations to OC.
03-02-10 01:56 AM
03-02-10 09:12 AM
03-02-10 09:19 AM
2 - yes pull battery for 30seconds and replace
3 - not sure, can post this in another thread on its own
03-03-10 09:07 PM
Jon
03-03-10 09:40 PM
Jon
Please post your specific system related questions in a new thread. This thread should be for comments or questions about the guide only, thanks
03-13-10 10:34 PM
Dom
03-15-10 09:37 PM
03-16-10 04:20 AM
Im using p55m-ud2 mobo + i3 btw. When im trying to tweak my vcore how do i increase it in increments of 0.025V? in the bios the only available options are 0.5V+, 0.550V+, etc. am i missing something here?
03-16-10 01:28 PM
Im using p55m-ud2 mobo + i3 btw. When im trying to tweak my vcore how do i increase it in increments of 0.025V? in the bios the only available options are 0.5V+, 0.550V+, etc. am i missing something here?
However, I think you may be wrong with your numbers. A bump of .50 is not possibly the smallest option on a mobo seeing that normal VID is between .98 and 1.3625 on Intel processors, so bumping up vcore .5 would essentially burn out your chip with too much heat and volts in one simple bump. lol So, I am assuming you mean .055v? Please make this correction before we proceed.
Dom
03-16-10 10:58 PM
However, I think you may be wrong with your numbers. A bump of .50 is not possibly the smallest option on a mobo seeing that normal VID is between .98 and 1.3625 on Intel processors, so bumping up vcore .5 would essentially burn out your chip with too much heat and volts in one simple bump. lol So, I am assuming you mean .055v? Please make this correction before we proceed.
Dom
03-17-10 12:08 AM
Thank you MIAH and all who contributed!
But what's missing from this picture?
03-17-10 01:21 AM
I left out the i5 950 just for you
03-24-10 03:54 AM
Right now my oc is sitting at
3.65 ghz
multiplier x22
bclock 166
vcore on cpu-z @ max load 1.072V
@ bios 1.09v
vtt - 1.20V or 1.10v (stock
ram volts - 1.50V (should this ever be increased)
I've pretty much followed your guide (ram timings, lowest multiplier,etc). I've found leaving the vtt stock while increasing vcore slightly to be just as successful as increasing the vtt and vcore.
Anyways in an attempt to oc a little higher I've experimented by slowly increasing vcore, and bclock to 169,170,175 and it would boot then continue to restart eventually loading default settings if i do not go into the bios. The highest vcore i had was 1.25v @ 172. I'm not sure what the problem is, what are some numbers i should be testing out?
i have not yet increased the ram voltage because i am not even sure if this should even be increased in the first place.
03-24-10 04:13 AM
03-24-10 11:48 AM
2nd question - what was the maximum stable bclock freq you found in step #1?
2nd question - what was the maximum stable bclock freq you found in step #1?
I'm not at home so i can't test the maximum stable bclock right now, but the highest i could get so far (with memory timings set manually and mem volt set to auto, mem at 2:6) was 185 block (what im aiming for) x 19 multi @ 1.08 vcore and 1.21 vtt (would you recommend leaving vtt at stock 1.10?) which posted at 3.51ghz. Everything else was set to auto. I tried running 185 x 21 loaded windows then got the BSOD. I ran prime95 before I left, and it was stable for 5 minutes @ 185 x 19. It's still running so ill check the stability when i get home.
I also ran prime95 overnight with the settings in my previous post and got an error after one hour so that one wasnt stable -.-.
I forgot to mention that when i set the mem timings in the BIOS 9-9-9-24, cpu-z reads it was 7-9-9-24. Is this normal?
Im trying to hit 3.9-4 ghz using the lowest vcore. If possible not exceeding 1.25 vcore.
Thanks!
03-24-10 07:05 PM
I'm not at home so i can't test the maximum stable bclock right now, but the highest i could get so far (with memory timings set manually and mem volt set to auto, mem at 2:6) was 185 block (what im aiming for) x 19 multi @ 1.08 vcore and 1.21 vtt (would you recommend leaving vtt at stock 1.10?) which posted at 3.51ghz. Everything else was set to auto. I tried running 185 x 21 loaded windows then got the BSOD. I ran prime95 before I left, and it was stable for 5 minutes @ 185 x 19. It's still running so ill check the stability when i get home.
I also ran prime95 overnight with the settings in my previous post and got an error after one hour so that one wasnt stable -.-.
I forgot to mention that when i set the mem timings in the BIOS 9-9-9-24, cpu-z reads it was 7-9-9-24. Is this normal?
Im trying to hit 3.9-4 ghz using the lowest vcore. If possible not exceeding 1.25 vcore.
Thanks!
So when you tested for high bclock, you were using 185MHz with 1.21V VTT correct? You also had the CPU multi at x19??? Try for max bclock again with CPU multi set to x12 or so. If your goal is for 185MHz bclock, then got 190MHz stable for at least 1 hour. You may need more VTT...1.21V is not a lot, running 1.35V is perfectly safe for an air cooled rig
Then go back to 160MHz and bump up the multi to you desired setting, and the CPU voltage to 1.25V, then 5MHz at a time test as described in the guide and see if you can get it back up to 185MHz bclock. You may not get there though with so little voltage. Most CPUs need at least 1.3-1.35V to get to 4GHz, but you'll never know until you try.
If you need more help, please start a new thread so this one can remain on the topic of the guide
03-24-10 11:31 PM
04-10-10 08:36 PM
FYI, I plan to use your guide MIAHALLEN. It's the best one I've seen and I already have it printed out.
04-11-10 01:10 AM
04-11-10 03:02 AM
04-11-10 11:26 AM
04-11-10 11:35 AM
04-12-10 06:26 AM
Specifications:
i5 661 (stock)
4GB PC3-10666 1333MHz
Asus P7H55-M Pro
Radeon 5770 1GB GDDR5
Dual Layer DVD Burner
Hard Drive: 500GB
Cooler Master eXtremePower Plus 600w
Case: Cooler Master Centurion 590
Windows 7 Home Premium 64bit
My goals:
I'd like 3.7-3.9Ghz Nominal with room for Intels' Turbo Boost taking me to 4Mhz. According to my research my target should be about a 150 -155 MHz bclk and near stock volt's.
I bought this system and installed BFBC2 after playing BF2 for years, it does ok, but I have to turn down AA, AF HBOA = off to get 50 fps. If I want 60fps I have to drop res from 1900
1a) IYOP, what's my bottleneck ? CPU or GPU ? I plan to O.C both if I have to.
1) Does the iGPU chipset switch off entirely when you add a graphics card into the mix ? Do I still have to tweak the BIOS settings for the iGPU as instructed in GUIDE or can I forget about them for the OC?
2) OC'ing parameters aside, resetting the BIOS to default settings is scary to me, I've never done it before, never had a reason to. Wasn't it config'd by the builder in the shop for my specific system ? Is there a chance that other important settings besides the ones used for OC' be affectied negatively ?
3) Please confirm... Disable Turbo-Boost and Speed-Step ? Disable before starting to OC or leave enabled ?
Thanks to all who respond !
04-12-10 06:47 AM
I bought this system and installed BFBC2 after playing BF2 for years, it does ok, but I have to turn down AA, AF HBOA = off to get 50 fps. If I want 60fps I have to drop res from 1900
1a) IYOP, what's my bottleneck ? CPU or GPU ? I plan to O.C both if I have to.
Lots of folks want to talk about bottlenecks, but it's a more difficuly question to answer than most people think. Why? Because it totally dependant on a ton of variables. But thank goodness you asked the question correctly, telling me all of the hardware and what you plan to run (BFBC2). In this case, I'd say your GPU will be a bit of a bottleneck in most instances, expecially at native resolution as you've already discovered. So if I was you, I'd try to get that thing OC'ed first....or upgrade it if you can afford it.
1) Does the iGPU chipset switch off entirely when you add a graphics card into the mix ? Do I still have to tweak the BIOS settings for the iGPU as instructed in GUIDE or can I forget about them for the OC?
The iGPU switches off entirely since you're using a dedicated card. Don't worry about it
2) OC'ing parameters aside, resetting the BIOS to default settings is scary to me, I've never done it before, never had a reason to. Wasn't it config'd by the builder in the shop for my specific system ? Is there a chance that other important settings besides the ones used for OC' be affectied negatively ?
No, the builder likly didn't change anything in the BIOS, and from the factory, it should be at defaults anyway, so resetting them to defaults won't likely change anything
3) Please confirm... Disable Turbo-Boost and Speed-Step ? Disable before starting to OC or leave enabled ?
You've layed out your goals pretty clearly for me, and I think they are attainable. So in your case no, do not disable them. Just up your bclock step by step, and check for stability. I wouldn't change any voltages either, auto settings should work fine. Although keep an eye on the voltage displayed in CPU-Z while you are stress testing to be sure the board isn't setting rediculously high "auto" Vcore...if it is, you may have to take voltage settings into your own hands. My guide was more targeted at users looking to push a little harder, say if you wanted to shoot for 4.5GHz or so...then you would most likely HAVE to disable those features mentioned....
Thanks to all who respond !
04-16-10 01:50 AM
05-21-10 07:05 AM
Kudos so far!
I'd appreciate any/all help.....
Questions:
to +0.2V in the text, or should it be by +0.2V? in Bclock voltages section
Should +0.5V of the CPU Vtt value be +0.5V above the CPU Vtt value in the Maximum safe memory voltage section
Is there such a thing as IOH on a LGA1156 motherboard with H55 chipset? What should you do with IOH when you have no PCIe cards (only using the Clarkdale iGPU)? in the Bclock voltages section
Is there such a thing as ICH on a ASUS LGA1156 motherboard?
By following the 3-step guide, should I be ignoring ASUS DOCP and XMP profiles?
Should I be enabling the ASUS Xtreme Phase Full Power Mode (instead of the Auto default)?
Should I be using Offset or Manual CPU voltage when I need to change it, or doesnt it matter?
Should I disable the ASUS CPU TM function during my OC testing?
Is the Uncore Frequency the same as the ASUS iGPU frequency on a Clarkdale CPU?
Is the QPI/CPU Vtt voltage the same as ASUS IMC voltage?
Is the memory multiplier ratio you are talking about the same as ASUS DRAM frequency?
At what point in this Guide do you re-enable EIST, C1E, C-State (which package limit?), and the CPU TM function?
Thoughts/Suggestions:
Start putting footnote references when something only does/not pertain to Clarkdale/Lynnfield/H55 or other chipsets/combinations
Consider adding a table of terminology you use vs. some of the common motherboard manufacturers (included at the end for my ASUS P7H55D-M EVO using the 903 BIOS)
Consider adding that the Clarkdale iGPU clock (x) should be calculated to be the default base clock (b) times the default iGPU clock (c), divided by (over) the OC base clock (a). So x=bc/a Example: an i-3 Clarkdale with its iGPU clock at 733 and default bClock at 133, and it is to be overclocked to 210, the iGPU clock should be changed to 733x133/210 464 (as a math teacher, I simplified a forum post here to make it easier to calculate)
terminology
o say SpeedStep (EIST) so the next person does not have to look it up
o say how IOH Core Voltage is related to certain Northbridge chips? Elaborate with another sentence? Is H55 Northbridge?
o Say how ICH Core Voltage is related to certain Southbridge chips? Elaborate with another sentence?
Spelling, if you want it even more professional ferquency, that should be than?, manufactures should be manufacturers search and replace
BIOS Setting Terminology:
3-Step Guide terms Relevant ASUS BIOS settings (2009December)
EIST SpeedStep Tech (enable/disable)
TurboMode Tech (enable/disable)
C1E C1E Support (enable/disable)
CPU TM function (enable/disable)
C-State C-State Tech (enable/disable)
C-State package limit setting (C1,C3, C6,Auto)
Ai Overclock Tuner (Auto, Manual, DOCP, XMP)
DRAM OC Profile (DOCP) (DDR3-nnnnMHz)
XMP Profile (High Performance / Frequency)
Bclock BCLK Frequency (up to 500)
Multiplier CPU Ratio Setting (choices depend upon CPU model)
PCIe Frequency (up to 200)
Memory multiplier? DRAM Frequency (choices???)
QPI Frequency QPI Frequency (choices???)
DRAM Timing Control section (Auto or manual settings)
Uncore frequency? iGPU frequency? iGPU Frequency (Auto / actual up to 1500MHz)
Xtreme Phase Full Power Mode (Auto/Enabled)
CPU Differential Amplitude (Auto or up to 1000mV)
CPU Clock Skew (Auto or delay up to 1500ps)
V-Core CPU Voltage (Offset or Manual)
QPI/CPU Vtt IMC Voltage (Auto / up to 1.9V w/0.02V step
VDIMM/DRAM DRAM Voltage (Auto / up to 2.2V w/0.02V step)
CPU PLL Voltage (Auto / up to 2.2V w/0.02V step)
PCH Voltage(Auto / up to 2.0V w/0.01V step)
iGPU Voltage (Auto / up to 1.75V w/0.0125V step)
Load-line Calibration Load-Line Calibration (Auto/Enable/Disable)
CPU Spread Spectrum (Auto/Enable/Disable)
PCIE Spread Spectrum (Auto/Enable/Disable)
...sorry if the table is not coming through straight...
05-21-10 07:39 AM
05-21-10 12:41 PM
I am working on an overclock that is stable with VTT at 1.17V. I am currently running my ram at 1.66V. I don't know what is better, running my VTT lower or perhaps making my VTT closer to my ram voltage. I assume you wrote that in to mean for the case where people are putting lots of voltage on their ram, but I'm wondering what's the best setting for my particular chip.
05-21-10 03:21 PM
I am working on an overclock that is stable with VTT at 1.17V. I am currently running my ram at 1.66V. I don't know what is better, running my VTT lower or perhaps making my VTT closer to my ram voltage. I assume you wrote that in to mean for the case where people are putting lots of voltage on their ram, but I'm wondering what's the best setting for my particular chip.
05-21-10 03:39 PM
I got a replacement cpu from Intel, and I've been messing with it. It has a very strange batch number, L003B806, and has a very recent pack date 4/27/10. Requires a lot more voltage than my last chip to be stable for LinX, but runs cooler than my last one by more than a few degrees, even at higher voltage. I'll test out some more when I get my Venomous X in the mail.
05-23-10 09:53 PM
to +0.2V in the text, or should it be by +0.2V? in Bclock voltages section
Should +0.5V of the CPU Vtt value be +0.5V above the CPU Vtt value in the Maximum safe memory voltage section
Thanks for those
Is there such a thing as IOH on a LGA1156 motherboard with H55 chipset? What should you do with IOH when you have no PCIe cards (only using the Clarkdale iGPU)? in the Bclock voltages section
No, all P55/H55/H57 based boards use a Platform Controller Hub (PCH), it should not need any adjustment for basic overclocking, leave on "auto"
Is there such a thing as ICH on a ASUS LGA1156 motherboard?
no
By following the 3-step guide, should I be ignoring ASUS DOCP and XMP profiles?
yes
Should I be enabling the ASUS Xtreme Phase Full Power Mode (instead of the Auto default)?
depends, for maximum overclocking potential, you should enable it. If you are concerned about saving power, you should leave it disabled
Should I be using Offset or Manual CPU voltage when I need to change it, or doesnt it matter?
manual (this corolates to the "power saving features" mentioned in my guide
Should I disable the ASUS CPU TM function during my OC testing?
shouldn't make any difference
Is the Uncore Frequency the same as the ASUS iGPU frequency on a Clarkdale CPU?
NO! The uncore on all LGA1156 CPUs has a fixed ratio in relation to the bclock frequency....the iGPU frequency can be adjusted in most H55/H57 BIOSes
Is the QPI/CPU Vtt voltage the same as ASUS IMC voltage?
yes
Is the memory multiplier ratio you are talking about the same as ASUS DRAM frequency?
yes
At what point in this Guide do you re-enable EIST, C1E, C-State (which package limit?), and the CPU TM function?
My guide is not geared to finding the best OC with these features enabled. If you intend to enable these features, then enable them from the start. This is because your OC limits will differ (will be lower) with these features enabled.
Thoughts/Suggestions:
Start putting footnote references when something only does/not pertain to Clarkdale/Lynnfield/H55 or other chipsets/combinations
Great idea, might have to do this on the next revision.
Consider adding a table of terminology you use vs. some of the common motherboard manufacturers (included at the end for my ASUS P7H55D-M EVO using the 903 BIOS)
While this would be idea, please keep in mind that this would be pretty difficult for me without having my hands on more equipment. I'm just an enthusiast doing this voluntarily at home. Currently I only have 1 LGA1156 motherboard and X58 motherboards from only 2 vendors.
Consider adding that the Clarkdale iGPU clock (x) should be calculated to be the default base clock (b) times the default iGPU clock (c), divided by (over) the OC base clock (a). So x=bc/a Example: an i-3 Clarkdale with its iGPU clock at 733 and default bClock at 133, and it is to be overclocked to 210, the iGPU clock should be changed to 733x133/210 464 (as a math teacher, I simplified a forum post here to make it easier to calculate)
This is covered in the section "Isolate the bclock from the iGPU (Clarkdale only)"....just without the formula. I think it's a good idea to add the formula though, thanks!
terminology
o say SpeedStep (EIST) so the next person does not have to look it up
o say how IOH Core Voltage is related to certain Northbridge chips? Elaborate with another sentence? Is H55 Northbridge?
o Say how ICH Core Voltage is related to certain Southbridge chips? Elaborate with another sentence?
Spelling, if you want it even more professional ferquency, that should be than?, manufactures should be manufacturers search and replace
Great suggestions, thank you!
05-24-10 07:05 AM
Thanks for the ultra-prompt response, considering you were out Several of those answers should, in some way, make it to the next revisionto ease the anxiety of the next person to test drive Maybe you could enlist the help of others here that are well-respected, to assist with a terminology table regarding motherboard manufacturer socket/chipset combos that you dont have at your fingertips...
Added Questions for The Guide:
Can you also add just a couple sentences in The Guide on the aims for different OCers? Is the aim to have a balance between the highest BClockxmultiplierhighest CPU-z Core Speed without having to sacrifice much memory underclocking in a i-3 Clarkdale using the iGPU? Used as a multitasking computer (A Gamer/Jedi I am not) when I need that last boost when concurrently doing huge Word Tables in my Chinese dictionary (Im struggling to learn Chinese), 100MB digital picture manipulations for the family history, or huge spreadsheet reiterative calculations? Or when Windows 8 requires even more processing power in a couple years? Or for bragging rights? Which is better, for example 182.4MHzx22 (4.013Ghz) w/memory at 729.6MHz, or 195MHzx20(lower 3.900GHz) w/memory at a higher 780MHz? And Why?
To try to overclock the iGPU do I just try to up the speed beyond the default (after calculation from the base)? What do I do with the 1.15v it by default AUTO-picks? Is there a non-ASUS utility that properly displays the iGPU frequency/voltage because CPU-z seems to have it locked at 733MHz and Im not sure I trust TurboV because it is the only source and seems to differ from CPU-z and others.
Leaving things in BIOS at the default AUTO setting I see ASUS wants to AUTO over-rate my memory to CAS8 (when shown in CPU-z) instead of the less expensive CAS9 mine is. When attempting to override (Should I override?), even the Memory Timings terminologies do not seem consistent between CPU-z and ASUS BIOS. Where do I set tRC? And how do I know the proper 2nd and 3rd ASUS sets of numbers in BIOS for my Corsair XMP 1600 memory? (wish I could put more characters regarding my system out here on the forum) Or is that translation table the subject of another Guide somebody wrote?
Should the IMC/CPU Vtt voltage generally be kept over or under the VCore voltage by a certain amount? Maximum difference?
Im just real anxious about permanently toasting something (dont like throwing $120 away) keeping a close eye to make sure CPU temps dont get above 65DegC. Can things get only somewhat damaged and not show up in definite ways until you go back to old/known good settings and find Prime95 is no longer stable or the CPU is running hotter than it used to? Or is it more burnt/not?
Thoughts/Suggestions:
Spelling - fine should be find
05-24-10 03:29 PM
Can you also add just a couple sentences in The Guide on the aims for different OCers? Is the aim to have a balance between the highest BClockxmultiplierhighest CPU-z Core Speed without having to sacrifice much memory underclocking in a i-3 Clarkdale using the iGPU? Used as a multitasking computer (A Gamer/Jedi I am not) when I need that last boost when concurrently doing huge Word Tables in my Chinese dictionary (Im struggling to learn Chinese), 100MB digital picture manipulations for the family history, or huge spreadsheet reiterative calculations? Or when Windows 8 requires even more processing power in a couple years? Or for bragging rights? Which is better, for example 182.4MHzx22 (4.013Ghz) w/memory at 729.6MHz, or 195MHzx20(lower 3.900GHz) w/memory at a higher 780MHz? And Why?
This is not a black and white Q/A....it depends on the app. But usually CPU speed trumps memory speed. And with the minimal differences you're aking about, both would feel about the same, but my advice would be to maximize CPU speed, not mem speed.
To try to overclock the iGPU do I just try to up the speed beyond the default (after calculation from the base)? What do I do with the 1.15v it by default AUTO-picks? Is there a non-ASUS utility that properly displays the iGPU frequency/voltage because CPU-z seems to have it locked at 733MHz and Im not sure I trust TurboV because it is the only source and seems to differ from CPU-z and others.
There is an app called "GPU-Z that should show the frequency, for voltage monitoring, Asus Turbo-V is the only option. Safe voltages for the iGPU are not known at this time. Most overclockers are gamers and therefore have dedicated GPUs and will not use the iGPU. But I do have a small amount of experience overclocking the iGPU due to a competition at HWBot.org a couple months ago. Many users were running the iGPU in excess of 1.4V and I did not here of anyone killing a CPU/iGPU during the contest. Having said that, if you are concerned about the health of the chip, I would recommend not giving the iGPU more than 1.3V until we have more data on the subject. BTW most of the Clarkdale iGPUs have been shown to easily break 1000MHz
Leaving things in BIOS at the default AUTO setting I see ASUS wants to AUTO over-rate my memory to CAS8 (when shown in CPU-z) instead of the less expensive CAS9 mine is. When attempting to override (Should I override?), even the Memory Timings terminologies do not seem consistent between CPU-z and ASUS BIOS. Where do I set tRC? And how do I know the proper 2nd and 3rd ASUS sets of numbers in BIOS for my Corsair XMP 1600 memory? (wish I could put more characters regarding my system out here on the forum) Or is that translation table the subject of another Guide somebody wrote?
Interesting, usually "auto" does just the opposite
Should the IMC/CPU Vtt voltage generally be kept over or under the VCore voltage by a certain amount? Maximum difference?
There is no specific rule for this, as mentioned in my guide the 32mn CPUs are more fragile to Vcore....but what I need to add, is that they are alse sensetive to too much VTT voltage as well...you shouldn't need more that 1.25V anyway.
Im just real anxious about permanently toasting something (dont like throwing $120 away) keeping a close eye to make sure CPU temps dont get above 65DegC. Can things get only somewhat damaged and not show up in definite ways until you go back to old/known good settings and find Prime95 is no longer stable or the CPU is running hotter than it used to? Or is it more burnt/not?
It is not uncommon for CPUs to become "degraded" as opposed to just flat dying. But usually these bad things happen a bit closer to the limit. Although there is risk in ANY overclocking, IMHO the bennefit outweighs it by a mile
05-25-10 04:34 AM
I am also facing a weird problem, my computer hangs and slows badly while multitasking having a quad core processor . I have checking my CPU usage while running processes which is normal . Tried on XP and Windows 7 and it was a nogo ..please help someone !! . Here are my specs.
05-25-10 07:35 AM
To best assist you, I'd recommend starting your own thread rather than tacking this on to the end of this one. It seems you have issues that need to be addressed before you begin attempting to overclock.
I'd recommend starting in the Microsoft Operating Systems area. If it's determined to be hardware instead of software, it can be moved to the appropriate section. Be sure to list the applications and background tasks you have running when you experience the hangs. Best of luck!
06-14-10 05:31 PM
06-14-10 07:10 PM
06-16-10 06:52 AM
Only problem I have now is to make a good chunk of time available to try this out without the gf complaining to much...
06-16-10 06:53 AM
Here my i5-661 @4,7Ghz LinX and Prime stable
06-16-10 09:31 AM
Only problem I have now is to make a good chunk of time available to try this out without the gf complaining to much...
Here my i5-661 @4,7Ghz LinX and Prime stable
06-21-10 09:27 PM
where i come from, it's very hot, like always in the 30c ~ 34c range. 100% load on my stock intel cooler can easily hit 90c.
even thou, u made me dauntless in my impending attempt to OC, at least to 4ghz.
Thanks
06-21-10 10:01 PM
06-22-10 01:41 PM
Nice....thanks for stopping by
Been doing some initial testing and I've managed to get my i7 860 up to 3,8GHz (BLCK190*20) so far... the voltages I've used are 1.3V for VCore and 1.3V for VTT - With that I'm stable for a full night, and temps keep between 75-79C running Prime95 which means I can do most of my "stuff" at temperatures around 70C.
I do have serious problems taking the step up to 4GHz though, because right now I just don't have sufficient cooling for that... Need some better fans in my box first (but that's a question for the "cooling" section.
Anyway - Thanks again for the guide, now I'm looking forward to the next step!
07-17-10 02:28 PM
07-18-10 02:32 PM
If you leave the QPI ratio on "auto", most motherboards will set it to x36 when you OC....and that would be fine. If you'd like to set it manually, do so at x36. And no, there would never be a need to change that unless you want to push the bclock to the limit for benching (not for everyday use), in that case "slow mode" sometimes helps a bit