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Dolk's Guide to the Phenom II

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I once overclocked an Intel
Mar 3, 2008
Small updates have been made on the original Phenom II overlocking section to reflect other updates, including the now gone 4.0ghz Section, and the new revised Heat Wall section.

The Heat Wall has been updated and revised. I really didn't like what I had before hand.

Thuban Section includes how to overlock B.E. Thubans.

What is to come ahead:

DDR3 Overclocking section. Right now the guide only refers to DDR2 overclocking, as it is a bit similar there are some neat tricks that I would like to share.
Unlocking with the 8-series Chipsets. Now its a flick of a switch instead of going into bios.
Turbo Mode. I can't seem to find that button on my case :shrug:


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Table of Contents


  • Introduction to myself and this guide
  • Introduction to the Phenom II
  • A look at the Architecture
Overclocking the Phenom II

  • System Setup
  • Overlocking the Phenom II
    • Memory
      • DRAM Frequency
      • RAM Timings
    • CPU
    • Northbridge
    • Putting It All Togeth
      • Finding your FSB Max
      • Overclocking the CPU
  • The Heat Wall
Phenom II Thuban Overclocking Section
  • Initial Thoughts
  • System Setup
  • Overclocking the Thuban
    • Overlocking with the Thuban B.E
    • Overclocking with the Thuban Standard
  • Turbo Mode Activate!
  • Unlocking to 6
Helpful Information

  • Benchmarking and Stress testing tools
    • Stressing
    • Benchmarking
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I have created this guide for anyone that has or is thinking about the Phenom II as their next processor. I first have to say that you are making the right step in choosing a Phenom II. This guide is intended to give a user massive amount of information about the Phenom II. Please take your time when reading this guide, you will most likely refer back to some of the content.

Introduction to myself and this guide

My name is Dolk and I am addicted to Overclocking. I have more than 5 years of computer IT jobs and computer work under my belt. I have done just about everything you could do with a computer. Fortunately, I was able to build my very first computer in 2007 consisting of an AMD 939 system. I immediately got into the fun of overclocking and by 2008 I had overclocked an Opteron 185 to 3.0ghz. Soon after doing that I got my first water cooling system. My admiration of overclocking lead me to the Phenom II. Right from the start I knew that the CPU was powerful and that everyone was going to enjoy using it.

As for the guide; The reason behind this guide is not only to learn how to overclock the Phenom II, but also to learn more about it. I have broken the guide up into three different parts. Please take the time to read each part and not to skip over anything. The guide was written in order from top to bottom so everything is referred to something in the past that was talked about.

The first part of this guide talks about the war between AMD and Intel, along with information about the Phenom II line up and the Dragon Platform. Although this section is not necessary to the guide, I thought it would help bring some background information to those that are new to overclocking.

The second part of this guide is about how to overclock the Phenom II. The architecture will be discussed along with the different methods of overclocking your Phenom II. There are a couple general rules that are discussed in this section.

The third part to this guide is the results that I have gathered with my Phenom II 940 BE and some helpful information that you can use later on in your overclocking. The topics discussed can help solve some issues that you may have run into in the past. Along with this section is my closing to this guide.

I will also use a bunch of terms throughout this guide. I decided that I should put this here instead of at the end of the paper so that people are not confused and then realize the cookie at the end of the paper and then read it all over again, but then that would allow people to read this paper more so now I’m at a conundrum while writing this, and I also do not want to end this really long sentence. Ha! Made you re-read that part. Anyways, here you go:

CPU = Central Processing Unit
NB = Northbridge
CPU-NB = CPU – Northbridge (redundant I know)
HTT = Hyper Transport
HT or HTL = Hyper Transport Link (do not confuse with HTT)
FSB = Front Side Bus (The FSB also refers to the HT/HTL)
OC = Overclock
BE = Black Edition (unlocked multiplier CPU)

Update to reflect Thuban

Introduction to the Phenom II

The Phenom II is based off the K10 architecture designed by AMD. It is the upgraded CPU of the Phenom I Agena series. The Agena was AMD’s first true quad core processor. The Phenom I was designed around a 65nm wafer using up to 140 watts of power. In general, it was good for the price you paid for it. Although you were not able to overclock it like an Intel, it did what it was suppose to do.

After a year of the Phenom I, the Phenom II came out. Deneb was a true 45nm quad core processor. Before it was released, many computer enthusiasts believed that the Phenom II was the processor to nock Intel off its throne. Even though it did not fulfill that expectation, it did however bring about a new way to overclock AMD processors.

The Phenom II was first released early in January of 2009. There were two CPUs released for the AM2+ architecture. They were the Phenom II 920 and 940. The 920 was clocked at 2.8ghz with a locked multiplier. The 940, also known as 940BE or Black Edition, was clocked at 3.0ghz. Both processors were clocked higher than any stock AMD processor before it.

The AM3 Series soon followed after the release of the initial set. In February the Heka series was released. This was the X3 series Phenom II. The initial release was the 710 and 720. When the 720 hit the market, there was such a high demand that some stores ran out of the CPU almost immediately. The 720 is one of the best well rounded CPUs on the market. It allows anyone to overclock up to 30% and beyond using stock cooler, and it also handles many of the tasks a 4-core processor handles.

Rewrite above to reflect new changes, including Thuban

A look at the Architecture

Phenom I

Agena (65 nm SOI)
  • Four AMD K10 cores
  • L1 cache: 64 KB + 64 KB (data + instructions) per core
  • L2 cache: 512 KB per core, full-speed
  • L3 cache: 2 MB shared between all cores
  • Memory controller: dual channel DDR2-1066 MHz with unganging option
  • MMX, Extended 3DNow!, SSE, SSE2, SSE3, SSE4a, AMD64, Cool'n'Quiet, NX bit, AMD-V
  • Socket AM2+, HyperTransport with 1600 to 2000 MHz
  • Power consumption (TDP): 65, 95, 125 and 140 Watt
Phenom II

Deneb (45 nm SOI with Immersion Lithography)
  • Four AMD K10 cores
  • L1 cache: 64 KB + 64 KB(data + instructions) per core
  • L2 cache: 512 KB per core, full-speed
  • L3 cache: 6 MB shared between all cores
  • Memory controller: dual channel DDR2-1066 MHz(AM2+), dual channel DDR3-1333(AM3) with unganging option
  • MMX, Extended 3DNow!, SSE, SSE2, SSE3, SSE4a, AMD64, Cool'n'Quiet, NX bit, AMD-V
  • Socket AM2+, Socket AM3, HyperTransport with 1800MHz
  • Power consumption (TDP): 125W
  • Six AMD K10 cores
  • 45 nm SOI with Immersion Lithography and Low-k insulator
  • L1 cache: 64 kB + 64 kB (data + instructions) per core
  • L2 cache: 512 kB per core, full-speed
  • L3 cache: 6 MB shared between all cores.
  • Memory controller: dual channel DDR2-1066 MHz (AM2+), dual channel DDR3-1333 (AM3) with unganging option
  • MMX, Extended 3DNow!, SSE, SSE2, SSE3, SSE4a, AMD64, Cool'n'Quiet, NX bit, AMD-V
  • Turbo Core
  • Socket AM2+, Socket AM3, HyperTransport with 2 GHz
  • Power consumption (TDP: 95 and 125 Watt)
  • Clock rate: 2.6 to 3.2 GHz, up to 3.6 GHz with Turbo Core
  • Models: Phenom II X6 1055T, and 1090T
Phenom II number naming scheme:

·1000-series - hex core - 6MB L3 cahce
·900-series – quad core – 6MB L3 cache
·800-series – quad core – 4MB L3 cache
·700-series – triple core – 6MB L3 cache

Secondary number naming scheme: (May not reflect Thuban)
·X55 – 3.2GHz (AM3)
·X45 – 3.0GHz (AM3)
·X40 – 3.0GHz (AM2+)
·X20 – 2.8GHz
·X10 – 2.6GHz
·X05 – 2.5GHz

Stock Voltages:
·CPU voltage ≈ 1.35v
·CPU-NB voltage = 1.175v
·HTT voltage = 1.2v
·SB voltage = 1.26v
·NB voltage = 1.1v
·CPU VDD = 2.5v

For more information on the standards of the Phenom II CPUs, please read the AMD Power and Thermal Data Sheet.
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Overclocking the Phenom II

Overclocking the Phenom II

Overclocking the Phenom II is a simply complicated task. What I mean is that you will be able to overclock right from the start with no problems, but as you go higher in clock speeds things become more difficult.

In this first section, I will be talking primarly about how to generall overclock your Phenom II. In the other sections I will be talking more indepth about the Phenom II and how it behaves. There is also a section about how to overclock the Phenom II Thuban, but it is more about the new tricks it has compared to the old Deneb CPU.

Note: Please be familiar with your motherboard BIOS. All settings that I talk about will be located in your motherboard BIOS. Each motherboard is different and you should learn what each setting is before beginning to overclock.

System Setup

Alright so before all of this information hits you, here is the hardware I used.
  • Phenom II 940 Stepping 2
  • Asus M3A79T-Deluxe Bios Version 0602
  • OCZ Reaper 1066 Cas 5 4gigs (2x2gig sticks)
  • MSI 8600GTS
  • 1TB (multi-partitioned) SATA HDD
  • Rocketfish 700w Power supply
  • Antec 900 with 3 120mm fans and 1 250mm fan
  • Cooling:
    • Stock AMD heatsink + fan + thermal paste (if stated)
    • Swiftech H20-220-APEX-GT CPU Liquid Cooling Kit
  • Windows 7 64-bit, Windows Vista 64-bit, Windows XP 32-bit (if stated)
Overlocking with the Phenom II

In this section I will finally teach you how to overclock the Phenom II. In general, the Phenom II is typically an easy processor to overclock. In no time, you should be able to go from 0% - 29% using your stock cooler and thermal paste. But going above and beyond, things will start to become more complicated. Things become even more complicated as you try to factor in a higher benchmark scores with your benchmarks.

For the rest of this section I will talk about each individual part that you will need to overclock. For beginners, I suggest that you read everything before acting. It will allow you to understand how things work.


First thing is the basics of RAM. Your RAM has a direct link to your CPU; there is no chip in between. This means that the CPU has an IMC (Integrated Memory Controller). There are two parts to the RAM : DRAM Frequency, and RAM Timings.

DRAM Frequency

The DRAM Frequency is the speed of your RAM. For the Phenom II there are four different basic frequencies. They are: 400, 667, 800, and 1066. Each of these speeds has a ratio. These ratios are what determine the speed of your RAM. The ratio is the FSB (Front Side Bus) and the DRAM Frequency [Seen as FSB : DRAM] . Table 1 should help explain everything. The DRAM Frequency can be changed based on the FSB. Using one of the ratios and a simple equation, you can determine the speed of which your RAM is running.


DRAM Frequency = [ (FSB * DRAM Ratio) / FSB Ratio ] * 2

For example I will calculate 1066 RAM: (Using standard AMD Settings)

200 * 8 = 1600
1600 / 3 = 533.333
533.33 * 2 = 1066.666

Now let’s say you have a 266 FSB. Still using 1066 RAM Ratio we would get these new results:

266 * 8 = 2128
2128 / 3 = 709.333
709.333 * 2 = 1418.667

You now have some really fast RAM, in fact this is most likely not possible for most RAM. But now you get the general idea. The FSB of your CPU will determine the speed of your RAM. By using the equation from above you will be able to calculate your RAM speed. This will serve as a very useful tool as you overclock your Phenom II.

NOTE: When configuring the ratio of your RAM, not all BIOS’s will not be the same. Each motherboard maker has their own way of making their BIOS. Please consult your motherboard manual to determine how to configure your RAM ratio.
The RAM ratio will be shown in one of two ways depending on your motherboard maker. First way is the basic ratio, just like my table from above. The menu will allow you to choose the ratio you want. The second way will be the showing of the four basic DRAM Frequencies. They will go in order 400, 667, 800, and 1066. These numbers represent the ratio you want.

RAM Timings

Now that you know how to determine the speed of your RAM, you can now set the Timings of your RAM. Depending on your motherboard maker, you will be able to fine tune your RAM timings. Your RAM timings represent the number of cycles it takes for information to be processed. There are several different types of timings you can modify but there are only six that you will want to work with. I would suggest that you do not touch the others unless you know what they do.

The six timings that you will tweak are: Cas Latency (CL), RAS# to CAS# Delay (tRCD), RAS# Precharge (tRP), Cycle Time (tRAS), Bank Cycle Time (tRC), and Command Rate (CR). These timings are directly affected by the speed of your RAM. Depending on your RAM manufacture there are a couple basic timings that you will most defiantly use while overclocking the Phenom II. Each timing works with a corresponding DRAM Frequency. NOTE: Please consult your RAM manual to find your RAM timings, my list is considered a default for each speed, but your RAM could be different.


The timings are most commonly represented as CL-tRCD-tRP-tRAS. For example: 5-5-5-15. For now, the default timings of your RAM should prove to be the best for overclocking in the 3.0 GHz range.
In some cases you will have to change the RAM timings to something unusual. In most cases it creates a more stable environment. I have found that using a 5-7-7-27-32 1066 Ram Setting in a 64bit environment is more stable than a 5-5-5-15 1066 or 800 Ram Setting.


The Phenom II is separated into two parts: Part 1 is the cores of the CPU. Part 2 is the NB, and HTT. In fact the Second part of the CPU is actually just the CPU-NB. The HTT and a couple other things are what make up the CPU-NB but to make things easy on you, I will talk as if the CPU-NB and the HTT are two different entities. (Which they are in reality but in hardware not so much, but then again are one in the same. Confusing isn’t it…)

For the first part of the CPU, you have the cores. The cores are connected by the FSB or HT Link (HTL), even the CPU-NB runs on it. The FSB always has a stock frequency of 200 MHz. The core is then multiplied by the CPU Multiplier to create the actual speed of the core. This is also applied to the CPU-NB, and HTT.

In order to overclock your computer, most people would simply increase the FSB. In 90% of all cases this is true, the other 10% of people have something called a BE or Black Edition CPU. These CPUs have an unlocked multiplier and will allow the user to just increase the multiplier of the cores thus increasing the speed of the CPU. So let us look at how the FSB and Multiplier can be used to overclock the CPU. For my first example I will use the Phenom II 810. This CPU has a stock speed of 2.8 GHz.

Stock: 200 * 14 = 2800 MHz
In other terms
FSB * CPU Multiplier = Speed of CPU

With the 810, I can only increase the FSB in order to overclock the CPU itself. So for this next example I will increase the FSB to create a 3000 MHz CPU or a 3.0 GHz core speed.

OC: 215 * 14 ≈ 3000 MHz

You roughly have a 3.0 GHz CPU now, in fact it is a tad bit faster, but that is ok.
For this next example I will take a Phenom II 940 BE CPU and overclock it. Remember the BE CPUs have an unlocked multiplier so you will not have to increase the FSB to get a higher clocked CPU. There are many benefits to this and they will be discussed in detail later in this section.

OC: 200 * 15 ≈ 3000 MHz

With just using the CPU – Multiplier I was able to up the CPU speed to a clock speed of 3000 MHz or 3.0 GHz.

One question that is probably in your mind is: Is there a difference between increasing the FSB rather than the Multiplier and vice versa? In truth no. If you have a BE CPU, there is no difference other then what will be talked about later in this section. But for a CPU that has a core speed of 2.8 GHz that and is increased to 3.0 GHz either technique will not create a faster CPU if you increased the FSB or the Multiplier or both. Just know that the FSB will affect other things then the CPU core speed.

Now that you understand how to overclock your CPU. Let us look at the second part of the CPU. The second part contains the CPU-NB, and HTT. In here everything is still connected by the FSB of the CPU, and each part has its own speed. So, the CPU-NB and HTT have their own speeds, and they work the same way as the CPU cores. Simply put, they both have their own multiplier and they go off the FSB. For example let us look at the 810 once more at stock speeds.

200 * 14 = 2800 MHz Core Speed
200 * 9 = 1800 MHz CPU-NB Speed
200 * 9 = 1800 MHz HTT Speed

As you can see its just as simple as the CPU core speed calculation. One thing you should notice right away is that the CPU-NB and the HTT are using the same multipliers at stock settings. Remember they have their own separate multiplier but they do in fact run at the same speeds at stock. One thing to note and always remember is that the HTT can never go higher than the CPU-NB speed. The speed of your CPU-NB is the max speed of your HTT.

There are several different methods to overclock the HTT and CPU-NB. First way and what should always be done, is just increase the multiplier. No matter what Phenom II CPU you have, you can always increase the multiplier of the HTT and CPU-NB, but there will be a constriction, albeit a constriction you should never see. The other way is to increase the FSB. I will use the 940BE in this example to overclock everything.

Overclock using Multiplier:
200 * 15 = 3000 MHz Core Speed
200 * 10 = 2000 MHz CPU-NB Speed
200 * 10 = 2000 MHz HTT Speed

Overclock using FSB:
215 * 14 ≈ 3000 MHz Core Speed
215 * 9 = 1935 MHz CPU-NB Speed
215 * 9 = 1935 MHz HTT Speed

As you can see, very simple to understand. Now do not start overclocking your CPU just yet. There is still one more section to read before Putting It All Together. In the next section I will talk about the CPU-NB a lot more.


Whenever one is talking about the North Bridge (NB) of a Phenom II, it is safe to assume that they are talking about the CPU-NB. The CPU-NB is a section of the CPU that controls the L3, Memory Controller and the Hyper-Transport (HTT). As mentioned before the CPU-NB and the HTT have different multipliers, please remember this.

When you overclock your CPU, the higher you go the more likely you will need to stabilize the CPU-NB. What do I mean by this? As the CPU increases its speed to calculate data, so must the speed of which the CPU communicates with other components on the Motherboard: chipset, memory, etc. Let me take the classic example of a 4.0 GHz 940BE and its CPU-NB. If you were to leave the CPU-NB at 1.8 GHz stock then the data calculated by the CPU would create a bottleneck and thus resulting in errata errors or CPU errors. So in order to balance these speeds a CPU-NB clock of 3.0 GHz would be needed. In most cases of high OC’s that result in crashes; the CPU-NB is usually the culprit.

I have constructed a table at which your CPU-NB should be at with ‘Y’ CPU Speed. Please note that there is a +/- 200 MHz difference for each step. In order to find your speed without my table, you can use my formula: CPU-NB Frequency (+/-200) = (CPU-Frequency * 2 ) / 3.15.

Highlighted areas are the recommended speeds of which to run the CPU-NB

As you can see with Table 3, these are the support frequencies of your CPU-NB at X CPU frequency. Of course, as you increase the CPU-NB frequency, you have to increase the CPU-NB voltage.

Let me put this in practice, before you start to debate my theorem.


Highlighted areas are the recommended speeds of which to run the CPU-NB

Now that you have seen actual data charts you can criticize my theorem, do not worry I already do it myself. In practice it does not work 100%. Actually I have Super Pi 1M, 3D Mark 06, PC Mark 05 and Geekbench charts as well showing that the 2800 MHz NB usually is top of the charts rather than the recommended speeds by my calculations. Which to me, is fine. The idea behind the formula is a rough estimate of what you should be at with ‘Y’ CPU Frequency.

What you should get from this section is an understanding of the importance of the CPU-NB and how it effects your overclocking process. By all means you should think about looking at the CPU-NB each and every time when try to push for a different CPU Frequency.

Putting It All Together

So now that you have an understanding of how to Overclock your Phenom II, it is finally time to Overclock [rejoice].

If you have an unlocked or Black Edition Phenom II, you can skip the step: “Finding your FSB Max.” For the majority you will be overclocking the CPU by using the multiplier rather than the FSB. This is for most cases and up to a certain percent in CPU Frequency gain.

Finding your FSB Max

First thing to do is find the limit to your FSB [Front Side Bus]. You will increase the FSB by a factor of 10 then by a factor of 5 after that. With each bump, make sure to keep your CPU speed as close to its stock speed. For example if my stock speed is 3.0 GHz which is 15 multi and 200 FSB, when I get to 210 FSB my multi should be 14.5. Same goes with your HT, CPU NB Frequency, and the RAM timings, and ratio. Once your computer does not boot up any longer, this means you have found your FSB maximum. Now you can move on to seeing how far you can push your CPU.

Overclocking the CPU

add in info on using punched in settings for BIOS, and making sure nothing is set to AUTO unless for certain items

For those that have an unlocked multiplier, do not increase the FSB, rather increase the CPU Multiplier by a factor of one and follow the steps as written below. You do not have to worry about the FSB until later on in the game.

Now that you have found your FSB Maximum, you can now push the CPU to see how high of an overclock you can accomplish. Before we begin, you must understand that there will be a limit to the CPU, and you will have to accept it. Depending on your PSU, cooling, and hundreds of other factors, if you try to continuously push your CPU over the max, you could end up harming it. With that in mind let us get started.

Lower your FSB back to 200 stock speed, and bring your CPU multi back up to its stock value. Start pushing the FSB by a factor of 10, and then by a factor of 5. For each successful boot, make sure to run some sort of bench mark tester or stress test. Check the section titled: Benchmarking and Stress testing tools for more information. Once your computer starts to crash during boot or during the benchmarks, you will need to try 1 of 3 different options. Your first option is to raise the CPU Voltage. While this will work for the majority of the time, it does not work all the time. I would first try to increase the Voltage before exploring the other two problems. Your second and third option is to increase the CPU NB frequency and/or voltage. Please use table 3 and table 4 for more information on what NB frequency and Voltage you should be at. You should first try increasing the voltage before increasing the frequency. It tends to work better. You can push the CPU-NB voltage to a max of 1.40v. If you are having troubles with your overclocked CPU instead of increasing the CPU-NB try to bring it down. This same process will work as well with the HTT. For the most part you will not have to do much with the HTT but sometimes lowering it below stock will get you to the CPU speed you want. As a rule of thumb you should keep your HTT between 1200-2200 MHz when overclocking. The third option that you may want to try is messing with your RAM. You can do a couple of things with your RAM. First increase the Voltage from stock by 0.2v. This usually does the trick. You can increase the RAM voltage up to 2.1v or something similar for RAM that is already at 2.1v at stock. If this does not do the trick try working with the Timings and a different Ratio. Sometimes a 800 ratio is better than a 1000, or 1066 ratio and vice verse. Overclocking is not a very simple task. Sometimes it takes time to find the sweet spot for your CPU. Make sure to try a variety of different settings until you feel comfortable. Just make sure to work inside the limits of your computer and the limits I have mentioned in this guide.

As you continue to increase your CPU speed, make sure to watch the CPU temperature. Once it hits a maximum of 60C LOAD, you MUST STOP! You are close to damaging with the CPU if you go any further. If your goal is to make your CPU stable, you NEED to lower the settings to have the CPU LOAD temp at a max of 55C.
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The Heat Wall

The Heat Wall​

If anyone read this section before the revision, I told a tale about how I tried to get my Phenom II 940 up to 4.0 GHz using standard WC cooling. The only way to see the 4.0 GHz range was if the CPU was below a certain temperature. To this day, this theme is still applied to all AMD Phenom II and Athlon II CPUs. AMD CPUs love the cold, and in fact nine out of ten of the CPUs you will get from AMD will have the ability to operate at temperatures of -240C, but you will never see that because most of you are only running Air or WC systems. This section is not about extreme cooling; it is a more in depth look at the Phenom II CPUs to what is going on.

So here we have this thing, called a CPU. In it, is billions of electronic circuits called transistors. Each of these transistors has two states, open or closed (1 or 0, true or false). When a series of these transistors opens and closes it creates a pattern with the electric flow. The electric flow turns into electric signals and the signals are interpreted to be functions. These functions can then be interpreted once more as a request by something to do something. For example, a request is made by the mouse click to play a video. The mouse click goes to the CPU, the CPU reads the pattern of electricity as a mouse click that needs to open a video, the request for the video information is sent to the OS on the HDD, and the information to display the video is sent to the GPU. This is Computer Information 101 (also known as A+ Certs).

One thing people tend to forget about with electronics is the energy. Not the energy as in how much you are saving between idle and stress testing, but the actual physics of electrons moving inside a chip. In this universe, all actions taken require energy, either by absorbing or by releasing energy. In the case of Computers, energy is released for every switch of a transistor. To get a bigger ideal as to what is going on, a 1.0 GHz signal means that a transistor just opened and closed 1 million times in a second. That is a lot of energy. All of that energy is released by this single second, and the byproduct of released energy is heat. This is Physics 101. Energy that is released produces heat, Energy that is absorbed produces an absence of heat; in other terms cold.

Now let us bring this to the big scale. As we all know, a CPU is first designed on a plate of silicon, where billions of transistors are housed. In conventional CPUs, there are now more than one section on the CPU. In the case of the Phenom II, there are the either 4 or 6 cores, with their own cache, including the L3 Cache, and the CPU-NB. As you can imagine, it is not hard to fathom that there are billions of transistors to make up each of these sections. In a Phenom II 955, the default core speed is 3.2 GHz, with the CPU-NB and HT at 2.0 GHz. That is to say that each core runs at 3.2 GHz. This creates a tremendous amount of energy. In fact, if you were to take off the heat sink, and somehow have the system continue to run, your CPU would be on fire in less than 5 seconds. Just keep that in mind.

Due to the special process of how an AMD CPU is made, the max temperature of an AMD Phenom II and Athlon II is 55C. If you want to know why, you should read the information above. Intel has a different process of making CPUs so in turn their max temperature is much different than AMD, but the difference that counts between the two is not max temperature but minimum temperature. With AMD’s special blend of silicon, the company has produced CPUs that have no Cold Bugs. Theoretically these CPUs could operate close to 0 Kelvin (absolute 0; in other terms, where atoms stop moving). While on the other hand Intel’s CPU can only operate at around -175C, but there are few that do not have a CB.

Anyway back on to topic. Why give you all this information? Why create a background instead of saying that NO MATTER WHAT the Phenom II and Athlon II will not increase in speed after reaching 55C on loaded temperatures. Let me repeat that, all Phenom IIs and Athlon IIs will not increase their speed (overclock) and more once the loaded temperature on the cores reaches 55C. The understanding is all explained above, but here is the summation. Due to high amount of energy produced by the CPU, and the special blend of silicon used by AMD, the CPU will not be able to operate any higher than 55C or it will literally start to get into a range of extreme temperatures that could cause the CPU to catch fire.

If you find yourself stuck at some point while trying to overclock your CPU, take a look at the temperature and see where you are at. If you are close to that 55C sweet spot, you have gone too far, and the only way to go faster, is to decrease the temperature of the CPU itself.
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Phenom II Thuban Section

Phenom II Thuban Overclocking Section

This section is still under devlopment, please be paitent

Another year, another model from AMD; this time it is not just an updated CPU, it is a new design off an old design. At first this part of the guide was going to be a huge refresh on how to overclock the Thuban model. After some time working with the Thuban, I learned that it is not a new chip; just an old dog with new tricks. Although I do have to admit that the new IMC design has changed the field a bit, and HTT is not what it used to be.

This time around we got four players on the field, instead of our usual three. CPU, CPU-NB, and RAM is what we have always focused on in order to achieve a stable overclock. Now we will have to use the HTT to create an even more stable environment.

As for now, this section will just be an update to teach you the new tricks of the Thuban. Later I will be adding more information about core unlocking, memory optimization, and IGP overclocking. This section will also retain to 8-series chipsets. As of right now, there is not a lot of support on the 7 series. What support there is on the 7-series is not reliable.

  • Phenom II 1090T
  • 4gig OCZ AMD BE (Stock 1600 Cas 9)
  • Radeon 4870
Overclocking with Thuban

Unlike the Deneb series, the Thuban will not contain a lot of Black Edition (BE) CPUs. People are going to have to go back to their roots and overclock with the HT. Usually this has not caused a difference in performance, at least for the Deneb. For the Thuban though, there is a difference. The cores of the 1055T are much weaker than those of the 1090T. Who knows how it will be when the different editions come out; if they do come out. As of right now, the 1055T, and the 1090T are the only two Thubans, and will remain as such. AMD is not wanting to create 4 core CPUs out of Thuban as of yet. This may change in the future though.

Let us finally get into the true nature of this section, overclocking the Thuban. I’m going to now separate this part into two sections. One is for Black Edition Thubans and the other is for Regular Thubans. The reason for this is that, even though both somewhat follow the same rules, it is easier for the reader to understand where to go and to learn from.
If this is your first time overclocking a Phenom II, please read the ENTIRE guide before starting to overclock. As a reminder this section only refers to THUBAN not DENEB (please see the introduction to this guide for more information about the difference.

Overclocking with the Thuban B.E.

You guys have it the easiest, like usual. But this time around I’m not going to just tell you what you need to do in order to achieve a high overclock. It is all about optimization these days; getting the fastest out of your hardware, down to the last clock of RAM. Are you ready to learn how to unleash the beast?

First thing is first, for all CPUs: find your walls. Even though you have this powerful chip, you are still going to have walls that limit you as to how far you can go. The main one being the Heat Wall (read more about that in my Heat Wall section).

First off let us find your max core wall. This will tell you how far you can go, and at what temperature you may be running at. Please note now that you will probably not be operating at speeds you will see. Sorry.
First thing you need to do is get up to 3.8ghz stable. This should be pretty easy as it you should only be using some stock voltages and a bump up on the CPU-NB and HTT. RAM should be at its default SPD settings as well. Turbo Mode should be completely off. Once you are nice and stable, get AMD OverDriver (AOD). This is a great tool to overclock your CPU in the OS environment. I do not suggest using it for 24/7 overclocking. This tool is designed to do exactly what I am showing you. You will also need Wprime version 1.55 and the latest version of CPU-Z. Make sure you have AOD open and CPU-Z open at the same time. CPU-Z will be used as an accurate tool to show what speed your CPU is at, and what Voltage it is at. AOD is not 100% reliable with this. At this time, you should double check to see if Turbo Mode is off. This will completely destroy any data that you will be gathering at this time.

Now that you are setup and ready to go, you will now start to increase the CPU-Multi by 1 and then hit Apply. Let AOD take its time in setting the CPU Frequency. Once it seems that your System will not crash, open up Wprime v1.55 and set the thread count to 6. Run 32M. If no errors are thrown, and your Computer continues to run, this is considered a theoretical potential overclock of your CPU. This does not mean you will be able to run 24/7 on these settings, it just shows that your CPU can handle an instance of intense benching, which means there is hope (sometimes very small). With each successful Wprime 32M run, close that program, increase the CPU-Multi by one once more, and hit Apply. Repeat Wprime test, then repeat CPU speed increase until either one of two things happen; either the system becomes unstable due to lack of voltage, or the CPU will get two hot. The Voltage issue is simple, increase voltage. You should know how high you will want to push the voltage, but please make sure not to go beyond 1.55v. The recommended voltage for 24/7 usage is 1.40-1.45v. If you run into a situation in when Wprime throws an error, this is considered a theoretical max as well. Although, the reason behind that error could be caused by RAM or CPU-NB, but for now we will consider this as a theoretical max.

With these Theoretical Maxes, you can now find the max stable overclock with your defined CPU voltage. You are going to need Prime95 or a similar tool for this next part. Here is where we starting finding your maximum CPU frequency speed, along with supported speeds with HTT and CPU-NB. In most cases your theoretical max speeds that you have found will not work under the Prime95 test, you may have to increase the CPU voltage, or find a balance with the CPU-NB and HTT. Run Prime95 without changing the settings (outside of CPU Multi, and CPUv) with a theoretical max and see if it is stable. If something goes wrong here is a common list of the error, explanation, and resolution as how to fix it.

• Core fails: This happens when a core calculates values outside the frequency causing errors. This can end up causing BSODS or Freeze ups. Voltage added to the CPU or CPU-NB can sometimes fix this problem.

• BSODS: This is caused by memory instability. The reason behind this is bad RAM or OCed RAM, or can be caused by instable CPU-NB. Changing the CPU-NB frequency to lower or higher settings may help stabilize the OC. Lossening RAM timings may also help as well or lower the Frequency of the RAM. Voltage may be added to the CPU-NB to help.

• Freeze Ups: This may be caused by overheating of the CPU or could be a precursor to BSOD. Check temperature to make sure that you are within range of Max CPU temperature. If this is not the case, follow BSOD instructions.

On a side note, I did mention that the HTT will be used a lot more with Thuban. For some reason, Thuban loves to have the HTT just as high as the CPU-NB. It creates a much more stable environment if you do this. But, on another hand, it may not work at all. There is a bit of mystery surrounding this phenomenon, of which I hope to figure out soon. As for now, just keep that bit of information with you.

As a second side note, some of the newer boards that use the 8-series chips now have a feature called LLC or Load-Line Calibration. This will allow a sort of fluctuation with the CPUv and CPU-NBv. This can be turned on or off. If on the voltage will have a bit of bigger area of which it can operate. These can potential even lower the voltage used when in idle mode. If off, the voltage will be set to the specific voltage that you have set in the BIOS.

Let us take a step back and look at what you have done so far. For now you have found theoretical maxes to your CPU. These are situations at which your CPU may be able to run at Y Voltage. With this Y voltage at X speed, you have been able to see if it is stable under Prime95 with A CPU-NB settings and B HTT settings (where A also includes CPU-NBv). RAM has been somewhat left alone at this point, staying relatively at stock speed and timing. If all has gone well, you should have found a high overclock that will is technically your max with the variables set by the theoretical max found by the AOD testing. As always the lord of all walls is the heat wall. If you have that wall controlled, your overclocking experience will be a better experience.

Turbo Mode Activate!

Unlocking to 6

Please note this very important piece of information!
*Deneb can be unlocked to 4 cores, and cannot be unlocked to 6. If you have seen pictures of people unlocking from 4 to 6, those are fake.
*Thuban can be unlocked to 6 cores. At this time there are only 6 core Thubans anyway, so this information is useless.

(This section is subject to change, depending on AMD's support of the X4 Thubans.)
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Thuban and 800 series Mobo

Benchmarking and Stress testing tools

Depending on whether you want a stable computer, or just benchmark it before it dies, you need the tools to do it. Here is a common list of tools and a strategy to both situations.


For most people, they want to use the overclock settings they obtained 24/7. To make sure these settings are stable you should use the tools below:
  • Prime 95: Use this tool to check full stability. Use it for 10 mins to learn if it is somewhat stable. Use for 12+ hours to learn if settings are fully stable
  • SuperPi 32M and 1M: Use this tool to check for somewhat stability. Best used to see if your computer can handle some benchmarks before shutting down.
  • Intel Burn In: A tool that is recommended by most to test for stability as well
  • Seti / Folding at Home crunching: Probably the best way to test if your computer is fully stable. Let run for 24+ hours, and you will know if your computer is 100% stable.

On the other hand some of you just want to score some great scores using benchmarks. This tends to be a lot of fun for most people. I personally love doing this in my spare time. For most people the following are the most common tools used for comparison of benchmarks.
  • PCMark 05
  • 3DMark 06, 03, and Vantage (Only for Windows Vista and 7)
  • CineBench
  • SuperPi 1M and 32M
  • wPrime
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K10 does not have FSB, I would recommend to use HT instead, FSB is so thunderbird barton era.

For finding your max HT drop the multi lower so the CPU max clockspeed can't limit you in finding the max HT which is likely to be limited by the board, dropping the ram can also help as 270+ can be easily too much for 800Mhz rams.

It is also a good idea to test each of your components as separated as possible (low multis for parts you do not want to stress) and find their limits before venturing to OC, this can save a lot of tinkering time with settings, to find out what holds you back. Then you know your limits and just dial in the config you want and see if it works altogether.
The HT Link also refers to the FSB of the CPU in most motherboard BIOS.

As for decreasing the RAM while increasing the FSB/HT Link: I do agree that you should first lower the RAM to something like 1:2 Ratio (800 MHz) and then increase, but you will most likely not hit at 270+ increase on the FSB, unless you have a good WC or anything better then that. For right now, that FSB setting is more then the 30% increase of a 920. If you are going above and beyond 30% increase of your CPU, you will have to wait for my second part of this guide.

I'll add your suggestion later Kuro, I just woke up and its time to eat ;)
Dolk i came across something odd which may only be a bug in the m3a79t, but when i was messing around with the northbridge and ht ref clocks i had set the nb multiplier to 4 to see if it still set the northbridge speed using the 250mhz i had the ht ref set at or the original 200. Anyways, i set it to 4x, then the post screen tells me a new cpu is installed, in the bios is called it an AMD engineering sample. Switching the multiplier up to 10 got me the same message on the next boot and it was now a phenom II 940 again in the bios.
Thats a bit odd, I don't think I have seen that before. Any chance you can recreate it and record everything? I have been looking into the absolute minimum amount of NB needed for a CPU OC, and your contribution will help.
change ht ref to 250, change nb multiplier to 4x, save and exit. I may be getting a vendetta 2 tomorrow so ill be alot more help after i get that installed
Its not the cooling, you may have stumbled on something, can you boot into it? Can you do anything with it? I don't believe this will hurt that CPU at all, but it may.
ya iwasnt sure if i would hurt anything so played it safe and set it back to default settings lol
ok that is very intersting I'm all most tempted to try it.
heh, using this guide i got booted into windows at 3.7, for some reason 3.7 will always lock windows up if i go that high in AOD, or not boot at all into windows if done in the bios. Adjusted the nb according to the guide, got a few runs of super pi in, really didnt want to do anything in the way of stress testing as i was at 1.50v and idling at 50c :( New cooler will really help
Good to here that it worked at least one positive feed back :D
Dolk, you've done a hell of a job with this research, I tend to float in and out of this board every year or two when I upgrade with the latest and greatest bang for the buck components... I've been overclocking for a good 12 years and I can't remember seeing someone lay it out this well... and they did throw some things for a loop with the release of the K10, admittedly I've had to learn a couple things.

Anyway, I'm :bang head since I apparently bought one of the few boards that can't adjust the NB multi (even though the option is listed) and because the FSB tops out at 240 MHz, nomatter the voltage on the chipset. Personally, I just think EVGA half assed this latest BIOS to quickly patch for the PII... I'm hoping they'll fix the BIOS issues by the next release... Everybody on the EVGA forums praises this board, sure it can clock the CPU like hell, but the rest of the options are SOL... Regardless, I'm quite happy with this CPU's dominating performance.
I have heard a lot of people not doing well with the Evga boards, along with BIOSTAR, and some other ocmpany.
Yeah, I shoulda stayed with my tried and true brand... Gigabyte, they've never dissapointed me... but I had to save $20 bucks. :screwy: Still, I can't complain about a 17100 3DMark06 score. :)