E8400@4Ghz - voltage help!!

palbarto

palbarto

palbarto

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HI All,

I have been running my CPU (E8400) at 3.6 GHz without any problems for quite some time now. I tried to reach 4GHz and I need some help with "fine tuning".

Everything goes good. 8 hours without any problems on Prime95, 3D Mark vantage runs ok and playing games without any issues. The problem comes when I try to convert movies to .mp4 (using Tipard Iphone Converter). After about 5 min from starting I get blue screen with error: Stop 0x124. When I put CPU back to 3.6 I can convert movies without any problems.

To reach 4GHz I only changed FSB to 445MHz and CPU voltage to 1.34V. Memory frequency sets itsef automatically when you changing FSB value on my motherboard. All other settings are on auto. Multiplier (set on auto) changes value between 6-9, so CPU doesn't have to run on 4GHz when not needed.

My config and settings:

E8400 @ 4.02 (445 MHz x 9), CPU voltage 1,34
Zalman CNPS9500A LED Fan (92mm)
Corsair Dominator PC8500 4GHZ (1069 MHz)
Asus P5Q-Pro
Sapphire ATI Radeon 5850
WD caviar black 640GB x 2 in Raid 0
Antec Skeleton Case
Windows 7 Home Premium 64bit

Any ideas how to reach perfectly stable 4GHz on E8400?
Thanks in advance
 
i used to have that chip, few years ago. if i remember i couldnt get it stable at 4 ghz at the time, i didnt have the tech i have now though togo with it to be fair. you should be able to get it to 3.8 easily enough.
 
Yup sounds like you will need more voltage for it to be stable when converting.

What i would do, as it seems fine in prime, is to raise the vcore a notch, then try and convert again, if it bsod's raise vcore again, continue doing this untill u reach the point where it will convert without issue.
 
That's what I was thinking. I read on Tom's Hardware that they put the chip on 1.36V in order to reach stability but when I did that temps went through the roof. I'll try stepping the Vcore a bit and let you all now what happens.

By the way ...

Anyone knows what is the max safe core temp for that chip as I do't want t fry it?

Thanks again
 
Max core temps 100c, so if u are still well under this no worries, ideally u want to stay closer to 70-80c though.

Max overall cpu temp 72.4°C
 
When you ran prime, was it blend or small fft.

May be worth checking volts for Dram and northbrige.

Don't go to high on vcore, i think the max was around 1.45v before it damaged the cpu.
 
Mines on 1.3875 I think and comes back at a lot less actual. I have a P5Q-E. Had it at 4Ghz stable as a rock forever.
 
You can safely go to 1.4v windows (cpu-z) load (100%), that could be a lot higher in the bios, but aslong as u stay below 1.4v under full load you will be fine, aslong as temps are fine ofcourse.
 
Yeah Ive put a load through mine, hasnt hurt it. Granted I dont need to put that much through it for 4ghz. Tried for 4.5 once but it was too much effort with FSB and the like. 400 FSB was too easy for me :D

I'll reply with my exact volts in 5 mins, give them all a try and see how you get on. Should be similar because of the boards.
 
i had no issues with fsb or anything like that i had a cracking mobo, if i remember rightly i had to give my old one like 1.475-1.5v for 4.5+ghz good thing i was on water cooling at the time, and it was only for benching sessions lol.
 
Hmm, well OK I may have been a little wrong about my voltages. I do have a E0 though :P

CPU Ratio: 9
FSB: 445
PCIE 101
FSB Strap 333

Mem OC Charger ON

Common Perf level 9

Vcore 1.30625
GTL - Both 0.67
Pll 1.56
FSB Term 1.26
Mem 2.12
NB 1.28
NB GTL 0.62
SB 1.1

LL Calib on

Make sure to set each voltage manually too, as the boards over-volt if left on default
 
Last edited:
I had to set about 1.41v in the bios to get my E7500 stable at 4ghz. But it comes in at more like 1.375 or so in CPUZ under load.

Apparently the max "safe" voltage for Core 2 Duos is 1.35v, so 1.375 is fine :D

Only gets to 50-55 degrees under load normally too :)
 
I've had mine running at 4Ghz since release.

Bios vCore: 1.375

Windows vCore: 1.34

Also as has been mentioned it is best to manually adjust your other v clocks as auto settings can be flaky at best.
 
Even though BIOS sets your memory automatically best check it is actually 1066mhz.
I have to manually change my RAM at 445mhz FSB.
 
SirCanealot said:
I had to set about 1.41v in the bios to get my E7500 stable at 4ghz. But it comes in at more like 1.375 or so in CPUZ under load.

Apparently the max "safe" voltage for Core 2 Duos is 1.35v, so 1.375 is fine :D

Only gets to 50-55 degrees under load normally too :)
Click to expand...

Thats intels max with there cooler for 45nm cpu's, with better cooling you can go over 1.375v easily. As its been proven by many many people.

Obviously the lower the vcore the better for temps, 1.4v windows load using an air cooler is fine for 24/7 use, as long as the temps are fine. That 1.4v loaded could equate to as much as 1.45v in the bios, depending on mobo.
 
The voltages to watch out for on 45nm cpu's is vtt/fsb term. 1.4 is the max reccomended on theese chips, vcore of 1.4v is good to stay below as well and NB of 1.4, i had both a q6600 and a q9550 on an asus p5q deluxe, both cpu's at 3.8ghz, the q6600 needed 1.58 pll, 1.34 on both NB and VTT, q9550 done it on 1.31 vcore and 1.26v on NB and VTT.
 
Last edited:
bilston said:
Hmm, well OK I may have been a little wrong about my voltages. I do have a E0 though :P

CPU Ratio: 9
FSB: 445
PCIE 101
FSB Strap 333

Mem OC Charger ON

Common Perf level 9

Vcore 1.30625
GTL - Both 0.67
Pll 1.56
FSB Term 1.26
Mem 2.12
NB 1.28
NB GTL 0.62
SB 1.1

LL Calib on

Make sure to set each voltage manually too, as the boards over-volt if left on default
Click to expand...

That's what I have set up in BIOS:
CPU Ratio: auto
FSB: 445
PCIE 100
FSB Strap 333

Mem OC Charger ON

Vcore 1.33750
GTL - Both - don't know what's this to be honest
Pll - same here
FSB Term 1.26
Mem auto
NB 1.28
NB GTL and same here as well
SB 1.1
I had leave RAM frq at 1069MHz (that's what my mobo was sugesting after putting FSB strap to 333MHz)

For now I managed to convert whole season of OZ without crashes. I'll run prime 95 and let you all know ...

fingers crossed and thanks for helping ...
 
I need some similar advice with my e8400.
It sits in a P5Q se2 next to 2x2gb 1066mhz dominators.
It passed 24hrs of prime95 at 3.6 but I have not adjusted any of the other voltages apart from the vcore. I would like to get it to 4ghz but last time i tried it one of the cores failed prim95 after 7 hours(the other was fine). Also one of my cores tends to run 3-7 degrees hotter than the other; is that normal?

One other thing to note, I am running my memory on 1:1 (800mhz) because when I put it up I had 'shutdown issues' which ment basicly my system would not fully power down and I have to hold the power button for 4 seconds to make the fans etc stop spinning. Not idea why this happened but I gave up trying to fix it and just had slighlty slower ram.

my case is raven02 and cooler is freezer 7 so cooling should not be a problem.

Any advice on what to do or even where to read up on chipset voltages would be a huge help.
 
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