OC'ing an E8500 CO on a P5Q-E

[Sixshot]

Hey guys, I'd appreciate your input here. As the thread title denotes, I have an E8500 with an Asus P5Q-E motherboard. I'm looking for 4 Ghz. I suppose I'd settle for 3.8, but I'd like to hit 4. I'm not really trying to push past 4 Ghz just to be safe. Sadly I do not have the E0 stepping model. I have never OC'ed before, and this is my first full build. What I need your help on is what settings to change in the BIOS. I understand it is bad to leave voltage settings and possibly some other settings on AUTO when OC'ing.


System specs

P5Q-E (1201 BIOS)
E8500 C0
Tuniq Tower w/ TX-2
4GB Corsair Dominator 1066 2 x 2GB (not using the airflow fan)
Corsair 550VX
VisionTek 4870 512MB
Four 120mm case fans and one 80mm case fan


Current SpeedFan temps idle/load (using Prime95 for load)

System: 21C/21C
CPU: 25C/31C
Core0: 31C/40C
Core1: 36C/41C


CPU-Z data

Core Voltage: 1.136 (@ 3.16 Ghz), 1.120/1.128 (@ 2 Ghz) w/ Speedstep & C1E enabled


The FSB and multiplier are both on AUTO in the BIOS (333 & 6.0/9.5). I'm aiming to set the FSB to 425. So the big question is...what should I change the voltage settings to? Not just the CPU voltage, but all that apply. NB, PLL...etc.

Thanks in advance guys!

 

[1ad7]

I just got the same mobo+cpu but mine is a EO, I just upped the fsb to 422 with only turning off the speed step and stuff etc... without adjusting voltage or anything. I will be pushing it past 4ghz but it was 15h prime stable at this setting 422x9.5 the guide helped me alot with settings to turn off

 

[unrlmth]

Up the voltage to around 1.3 and try for 3.8. If possible leave the other settings on auto. Turn off speedstep. Do everything in small increments and it helps if you write down your settings and results.


Like FSB 444x9 vCore 1.3 NB 1.4 Prime pass

 

[Sixshot]

Alright thanks, I'll just try to do it in small steps then..


Are you guys sure it'd be absolutely ok to leave stuff like FSB termination and PLL voltage on AUTO? Assuming I was gonna shoot for an end result of 4 Ghz, perhaps a tad bit over 4 Ghz, for 24/7 use?


Also is turning off Speedstep necessary? I kind of like the idea of having the chip automatically clock down when idle...

 

[redduc900]

PLL Voltage should be left at the default of 1.5 - 1.55v, and FSB Term. Voltage (VTT) shouldn't need to be increased to more than about 1.15 - 1.17 up to an FSB of 500 MHz. And vNB (MCH) shouldn't need to be increased past 1.4 - 1.45v, w/ 2 x 2GB RAM installed, until you reach the same FSB of 500 MHz. Also, it isn't necessary to disable SpeedStep (EIST) in order to achieve a stable OC (you can leave C1E enabled too, if that's an available option in your BIOS).

 

[ghost_recon88]

I would first update to the latest modded P5Q-E BIOS, the 1403m. Then set your FSB VTT to 1.1v, and your NB to 1.1v. You shouldn't have to increase your FSB VTT until after you pass 450MHz on the FSB. Your NB voltage may need to go up to 1.2v. Also use the 333MHz FSB strap and set the RAM to 1:1 that way you know its not the limiting factor in your overclock. Once you get your CPU maxed, then you can start tweaking the RAM.

 

[Sixshot]

Hey guys been a minute, thanks for your help btw. Here's what I got now...

First, I got 3.8 no problems...at 1.275 vCore (showed up as 1.256 in CPU-Z though). 400 FSB/9.5x. Left all other voltages on auto. Vista gave it a 5.8 (5.7 @ stock speed). Also temporarily disabled C1E & Speedstep, and set PCI-E to 100 Mhz even. Prime95 ran for like 5-6 hours with no errors.

I tried for 4 Ghz at the same voltage (425 FSB). Prime95 failed on one thread after like 2 hours 21 mins (I let it run while I was asleep, I think it actually ran for maybe 10 hours, the other thread hadn't failed). So I bumped the vCore up to 1.3 even. Vista gave the CPU a 5.9 @ 4.04 Ghz. CPU-Z reports a vCore of 1.288/1.280 at 4037 Mhz with a 1700 Mhz FSB. CPU temp in Speedfan peaks at about 34-35 celsius, with temps on the individual cores peaking at 50-51. System temp peaks at 25 (I'm assuming system is the northbridge?). Prime95 has been running for like 7 hours now with no errors.

I think I'm aiming to keep what I've got as far as frequency, 425 on the board and 4037 Mhz on the chip. But, do those temps look ok to you guys? Should I try to lower the vCore a bit more?

Do I need to fine-tune the GTL reference voltages? All voltages are on auto except vCore at the moment...I figured it'd be easier to troubleshoot that way while testing for stability with prime95. I know after I get the vCore to where it needs to be, I'm gonna work on vNB, and FSB term. Any other important voltages that need manual tuning I need to be aware of? Basically if any voltage is directly related to my overclock, I'm willing to fine-tune it, but if some voltages can just be left on auto, then I'd like to just leave them on auto.

I will try and tweak the RAM last, after I'm done with everything else. Not looking for much of an OC on the RAM though, maybe 1111. I've heard OC'ing memory is the riskiest component to try and OC, and I don't wanna risk much, even with the RAM I have.

I didn't update the BIOS, don't think I will...things are stable for me with 1201..

Lastly do you guys think 4 Ghz is fine for 24/7 use? Or should I back down to 3.8? Don't get me wrong though, I DO like 4 Ghz more for performance. I just don't want to degrade the chip, I want it to LAST. That's what's really important to me.

Anyhow, I look forward to reading you guys' thoughts.


edit: also, the max "safe" voltage for my chip is 1.3625 I read. Is that accurate?

and to redduc900 and ghost_recon88: One of you says 1.4-1.45 on the vNB and the other 1.1-1.2. What should I set it to first lol?

 

[Sixshot]

Well some bad news guys.


After more than 10 hours of prime (maybe 11 or so actually), my system just SHUT OFF. Like, not a BSOD or anything, and without warning. I turned it back on and it came on for like 2 seconds then turned off, then turned on again...thankfully though it stayed on that second time it came on.

I went into the BIOS and put everything back to default/auto. My system has NEVER just turned off like that, and I've had it built for months now. I at least was greeted by a BSOD first. This has certainly shaken me up a little bit.

I am not going to try and OC again until I can pin down why it just turned off abruptly like that. If any of you guys have any ideas, please let me know.

I can only theorize that MAYBE it was because some other voltage setting wasn't getting enough juice on AUTO? Like vNB or FSB term...hmmm....I'd like to HOPE it's something as simple as that...1.3 should be enough on the vCore right? I'd like to think so...I was hoping to put it at maybe 1.28 somethin

 

[doublejack]

A spontaneous shutdown or reboot can be caused by an unstable overclock. I know you feel shaken up, but it is a normal part of the overclocking process.

My thoughts are:

1. Definitely update your bios.

2. Your temps looked fine to me. I have a C0 E8400 and am hitting low to mid 50's on temps under full load. Anything less than 60 is very safe for 24/7 use.

3. You probably need a little more vcore to find stability at 4GHz. As long as you don't go any higher than 1.365V, which is the max voltage spec'd by Intel, then you won't do any real harm to your CPU. The jump from 3.8GHz to 4.0GHz isn't very big in terms of speed, but it seems these C0 processors need more voltage than you'd guess to bridge that gap. I was surprised how much I had to increase my vcore to hit 4.0

 

[Sixshot]

Thanks for your response.

Ok I guess I'll look into updating the BIOS.

Yeah I'm sure this is normal for OC'ing. It just turning off like that didn't sit well with me for a minute. I'll get over it and proceed though haha.

I wonder how much more vCore it needs. What did your e8400 need for 4 Ghz?

Is it ok to just leave the other relevant voltages on auto until I find a stable vCore? And is it at all possible that maybe it shut down because some of those other voltages should not have been on auto?

Thanks.

 

[Overbrazil]

but remember to not update the bios in a instable system.
make sure that is everything is default, otherwise, dont risk your mobo.

 

[doublejack]

I suggest leaving the other voltages on auto. I manually set them myself, but I've been doing this for a while now and am very comfortable with tinkering in the bios. In fact, I can't resist doing it. But for a beginner, it is easier to leave them on auto for now. You can always tinker later if you wish when you have some experience.

As far as my vcore setting, my e8400 will do 3.8GHz with 1.2625v and I have it running stable 24/7 @ 4.0GHz with 1.3375v. I had my vcore a couple notches lower, but apps were freezing up every great once in a while. More often than not, however, it takes more like 1.36v or even 1.4v to reach 4.0GHz with a C0 stepping chip.

The VID (stock voltage) of my e8400 is 1.15V. So it takes almost as much additional voltage to go from 3.8 to 4.0GHz as it does to go from the stock 3.0 to 3.8Ghz. The reason I mention this is the golden rule of overclocking - don't push further than you're comfortable with.

If you feel much better about running 3.8GHz with a lower voltage than you do about reaching 4.0GHz with a relatively higher voltage, then you may be better off with the slightly slower configuration. Because realistically, you won't notice and performance difference. I pushed to 4.0 for purely psychological reasons

 

[Sixshot]

Thanks doublejack. You've been really helpful.

So basically you're saying there's a good chance I might need to up the vCore BEYOND Intel's "max safe" limits. That's a really good point then. I am not even trying to go up to 1.35 quite frankly, 1.34 at the most.

I was under the impression that the e8xxx series could hit 4.0 pretty easily, as I've seen many people running 4.2 or more, even with the C0 chips. That is, without having to increase the voltage that much. Perhaps I stand corrected.

I think you see what I want though, which is a good overclock without any real risk. I am NOT a fan of the "by the time it burns itself out, you will have upgraded anyway" logic, and I'm not trying to degrade the chip over time, not even in the slightest.

I think I might just back down to 3.8. At least for now. If I feel like testing again later, and IF I can get it to 4.0 with 1.34 or less, then I might try again.

Anyone know what a good max safe FSB on my board might be? I'm wondering how much trouble/how safe 450 would be.

Also about my RAM...anyone here have any experience with the 1066 Dominators? What could I expect to safely OC them to? I'm not using the airflow fan, because I simply don't like how it's supposed to be "installed." My ambients are good though.

I was looking at my BIOS, and it seems you can't fine-tune the RAM frequency like that. It has a 1066 setting (and lesser speed settings before that), an 1111 setting, and like a 1333 setting. You guys think it'd be ok to set it to 1111? Also the timings are 5-5-5-18, by default (auto). I tried to manually set them to 5-5-5-15 once (which is what they're SUPPOSED to be @ 1066 Mhz), I got a random BSOD, and yeah it ****ed me off a little bit, so I put the timings back on auto (5-5-5-18), and haven't had any problems.

Not to get off topic or anything. I know the thread is supposed to be about my CPU overclock, but if anyone has something to add relating to my FSB or RAM speeds, I'd appreciate that as well.

 

[doublejack]

Thanks doublejack. You've been really helpful.

So basically you're saying there's a good chance I might need to up the vCore BEYOND Intel's "max safe" limits. That's a really good point then. I am not even trying to go up to 1.35 quite frankly, 1.34 at the most.

I was under the impression that the e8xxx series could hit 4.0 pretty easily, as I've seen many people running 4.2 or more, even with the C0 chips. That is, without having to increase the voltage that much. Perhaps I stand corrected.

You are very welcome The only thing I enjoy more than squeezing performance out of my own computer is helping others do the same.

Yes, unfortunately there are many C0 stepping processors that require more than Intel's "max safe" limits to reach 4.0GHz. I guess whether that meets the requirements of "safe" and "pretty easily" depends on how you define those terms.

Intel builds in a fudge factor into their max stock rating of 1.365v. Plus, there's some additional headroom from vdroop. So there's a gray area rather than an exact point we can all agree upon as "safe" voltage. Many members here have no qualms about going all the way to 1.365v, 1.4v, or even higher. My "don't go higher than" point was 1.4v. It's really a personal threshold.

As far as "pretty easily" reaching 4.0Ghz or higher I think that is true, but it comes with the caveat that more than "safe" voltage may be required. Just about all e8400's can run 4.0GHz 100% stable, the only question is how much voltage it takes. On the other hand, my prior CPU was an e6300 (now in my HTPC) and no matter what I did I had a lot of trouble getting it to run in the 3.0-3.2GHz range consistently. Meanwhile, there were other people running 3.5GHz all day long with a similar chip.

So basically, the 45nm processors are more uniform, have far more potential, and can be made to reach their potential without much real work - just possibly with some risk.

I think you see what I want though, which is a good overclock without any real risk. I am NOT a fan of the "by the time it burns itself out, you will have upgraded anyway" logic, and I'm not trying to degrade the chip over time, not even in the slightest.

I think I might just back down to 3.8. At least for now. If I feel like testing again later, and IF I can get it to 4.0 with 1.34 or less, then I might try again.

Yeah, that's what I thought. I'm mostly the same way. I'll take the extra "free" performance, but I don't like to risk my hardware. However, I am more willing to put my gaming system at risk... but only because I don't really use it for anything productive (for which I have other computers) and part of the fun for me is the gratification of pushing it.


Sorry I can't assist with the rest of your questions. I'm not familiar with your mobo or its chipset, nor that memory. My stuff is all older.

 

[Sixshot]

I think what I'm going to do actually, is keep trying to get 4.0 stable, and unless I'm really unfortunate and can't get there with less than 1.36 (Intel's max safe), or if my temps are too high, then I'll settle for 3.8.

Right now I've got it at the increment one step higher than 1.30 even in the BIOS, forget what it actually was, 1.306 something. In CPU-Z it shows up as 1.304 while running prime. Prime's been running for a couple hours now...looks hopeful I guess

Temps are a little higher than they were with 1.30 vcore, but of course the system just shut OFF with that, so it must not be enough. I think it was 1.288 in CPU-Z.

Should I be using Speedfan for temps? Is it ok/accurate?

Anywho, right now temps on the cores peak at 61-62, and the CPU temp peaks at 45-46. When someone says "60 or below," in Speedfan for instance, would that be the CPU temp or the core temps?

Yeah I just don't wanna go past 1.34 or so, because the chip simply shouldn't need that much more, going from 3.8, like you said. Not because it can't handle it, but because I don't feel the voltage is justified. You'd think I could hit 4.2 with 1.34-1.35. Hopefully though, I'll be able to run prime for more than a day straight @ 4.0 with less than 1.32 volts...

But this is my first time OC'ing, it's not like I know what to expect in terms of lifespan from experience, so I definitely want to stay under whatever Intel specifies as the maximum.

You aren't saying that the voltage needed for 4.0 would be any less safe for 24/7 use than the voltage needed for 3.8 though, are you? I just want my rig to work as good as it does now 3 years from now, if not 5 years from now. If you realistically think the chip would not last as long @ 4.0 as it would @ 3.8, then I'd certainly like to read your thoughts on that as well.

 

[doublejack]

Should I be using Speedfan for temps? Is it ok/accurate?

I've used speedfan. Some people prefer coretemp or realtemp. Nobody knows with 100% certainty what the actual temp of Tjmax is, so that's why you get slight variations in temp readings from one program to another. Intel's sensors give the delta between the observed temp and Tjmax.

Anywho, right now temps on the cores peak at 61-62, and the CPU temp peaks at 45-46. When someone says "60 or below," in Speedfan for instance, would that be the CPU temp or the core temps?

Usually it's core temps. But 60 is a very conservative "max temp" to go with, you can safely exceed that. Also, it is not common to load a processor in regular use or gaming to the point that a stress test does. So regular use temps are always lower.

Yeah I just don't wanna go past 1.34 or so, because the chip simply shouldn't need that much more, going from 3.8, like you said. Not because it can't handle it, but because I don't feel the voltage is justified. You'd think I could hit 4.2 with 1.34-1.35. Hopefully though, I'll be able to run prime for more than a day straight @ 4.0 with less than 1.32 volts...

You'd think it would be that way, but sometimes it isn't.

But this is my first time OC'ing, it's not like I know what to expect in terms of lifespan from experience, so I definitely want to stay under whatever Intel specifies as the maximum.

Intel offers a 3 year factory warranty. So they must have concluded that 1.3625V will not do enough damage in that time to degrade the cpu. There's probably a fudge factor in that calculation as well, as a company like Intel is not likely to take a risk. That's why many OC'ers consider 1.4V and under to be "safe".

You aren't saying that the voltage needed for 4.0 would be any less safe for 24/7 use than the voltage needed for 3.8 though, are you?

I'm just saying it is possible that the voltage needed for 4.0 24/7 operation may be less safe than the voltage needed for 3.8, or 3.6. It depends on what you find to be your chip's 4.0 24/7 stable voltage requirement.

I just want my rig to work as good as it does now 3 years from now, if not 5 years from now. If you realistically think the chip would not last as long @ 4.0 as it would @ 3.8, then I'd certainly like to read your thoughts on that as well.

With your 3-5 year window, I think as long as you don't go any higher than Intel's max spec voltage you'll be good to go.

 

[Sixshot]

Thanks again man. I know it seems like I asked the same question 5 times, but I just wanted as much feedback as I could get.


Well good news I think. I just woke up, and I actually slept longer than I expected I would...

Prime has been running for more than 33 hours straight with no errors. vCore in CPU-Z shows up as 1.304. In the BIOS I think I set it to 1.30625 (one step higher than 1.30000) *edit* actually I set it to 1.31250. Also I downloaded realtemp, and it shows the temps as being 10C lower than the core temps in speedfan, for what it's worth.

I guess I've found my lowest stable voltage then! Since it randomly shut off @ 1.30000 after like 11 hours or so. But I've been priming for nearly 34 hours now without a single error. This is great.

Now I just need to tune some other voltages, specifically FSB term and vNB, maybe PLL too. I've read numerous accounts of them overvolting on auto, and I just don't trust it for the long term.

So I guess I've successfully OC'ed this thing to where I wanted it to be...thanks so much guys for all your insight and info. I really appreciate it.

Cheers!

 

[Kucol]

Did you leave the other voltages on auto beside vCore ? Can you post screenshot or photo of your bios settings after oc ? Im going to buy almost the same comp setup and i want to oc my e8500 to 4ghz
thanks

 

[redduc900]

... and to redduc900 and ghost_recon88: One of you says 1.4-1.45 on the vNB and the other 1.1-1.2. What should I set it to first lol?

ghost_recon88 was right and I was wrong. I either hadn't realized it was a P45 chipset, or I just wasn't thinking right... sorry about the confusion.

 

[Sixshot]

Did you leave the other voltages on auto beside vCore ? Can you post screenshot or photo of your bios settings after oc ? Im going to buy almost the same comp setup and i want to oc my e8500 to 4ghz
thanks

Right now this is what my BIOS looks like (all voltages and other relevant settings):


CPU Ratio Setting: Auto
FSB Frequency: 425
PCI-E Frequency: 100
FSB Strap to North Bridge: Auto
DRAM Frequency: DDR2 1066
DRAM Timing Control: Auto


CPU Voltage: 1.31250
CPU GTL Voltage Reference (0/2): Auto
CPU GTL Voltage Reference (1/3): Auto
CPU PLL Voltage: 1.52
FSB Termination Voltage: 1.22
DRAM Voltage: 2.02
NB Voltage: 1.24
NB GTL Reference: Auto
SB Voltage: Auto
PCI-E Voltage: Auto


Load-Line Calibration: Auto
CPU Spread Spectrum: Enabled
PCI-E Spread Spectrum: Disabled
C1E: Enabled
Speedstep: Disabled


I probably have well over 100 hours cumulative in Prime with those settings, except the RAM voltage. I just got around to tweaking the RAM voltage, right now I'm 2 hours stable in Prime using blend mode. But, outside of RAM voltage, it is rock solid stable. Ran Prime once for 34+ hours, again for 27 or so, another instance for 25 or so, and at least once more, for 24 hours or more with no errors or warnings.

Temps are more than acceptable on everything. I'm still going to tweak the RAM a bit more, but everything else I think is done. At 1.20 on the FSB term and 1.22 on the NB, things were fine under Prime, but for some reason it wasn't posting at normal speed, sometimes it wouldn't load the OS at normal speed etc., so I bumped them both by one increment and it (seems to have) went away.

What do I see a huge improvement in? Crysis/Warhead. Everything else I do, and any other games I play, I can barely see any difference from stock speeds/settings.


edit: is 1.31250 (1.304 in CPU-Z under Prime full load) a good vCore for my E8500, @ 4.04 Ghz? I mean, is that a respectable vCore compared to what others typically get, for a C0 e8500 @ 4 Ghz? I'm curious.