E8400 - One core not stabile?

[wviperw]

Trying to OC my new E8400/PQ5 Pro setup and am testing for stability in Prime95. Unfortunately the first core appears to be quite a bit more stabile than the second, as evidenced by the durations below.

Is there a way to address this on a per-core basis without having to broadly apply more voltage to the entire CPU, or is that exactly what I need to do? Right now I've got my CPU Voltage set to Auto and it is reading off 1.296V in CPU-Z.

Worker Thread #1
[Oct 14 08:38] Test 1, 3100 Lucas-Lehmer iterations of M24903681 using FFT length 1280K.
[Oct 14 08:40] FATAL ERROR: Rounding was 0.5, expected less than 0.4
[Oct 14 08:40] Hardware failure detected, consult stress.txt file.
[Oct 14 08:40] Torture Test ran 7 hours, 35 minutes - 1 errors, 0 warnings.
[Oct 14 08:40] Work thread stopped.

Worker Thread #2
[Oct 14 01:16] Test 8, 4000 Lucas-Lehmer iterations of M18274367 using FFT length 1024K.
[Oct 14 01:17] FATAL ERROR: Rounding was 0.5, expected less than 0.4
[Oct 14 01:17] Hardware failure detected, consult stress.txt file.
[Oct 14 01:17] Torture Test ran 12 minutes - 1 errors, 0 warnings.
[Oct 14 01:17] Work thread stopped.

 

[nerp]

What speed are you at at that voltage?

 

[myocardia]

Depending on what FSB you're currently trying/running, the last post in this thread may help you out. You may just need more vCore, though, since both cores are ultimately failing. It's really not rare at all for core #0 to be the "stronger" of the two cores.

 

[wviperw]

Right now I'm at 9x400, memory at 1:1 (so 800), and 1.2v vcore and 2.0v dram. One thing I'm confused about is what exactly the FSB Termination Voltage does and what I need to set it to? Right now I have it on Auto.

 

[wviperw]

Tried upping the CPU vcore to the max recommended (1.3625v) and it is still failing out of P95 after 5-10 minutes. I don't get it--I thought E8400s were supposed to reach 9x400 without breaking a sweat?

 

[error8]

Originally posted by: wviperw
Right now I'm at 9x400, memory at 1:1 (so 800), and 1.2v vcore and 2.0v dram. One thing I'm confused about is what exactly the FSB Termination Voltage does and what I need to set it to? Right now I have it on Auto.

FSB termination is the voltage that links the cpu with the north bridge, or something like that. The trick is to not go over 1,4 V, since it can kill the cpu!!! And it's better to set it manually and don't let it on auto, since it probably tends to keep it at close as possible to the stock , which is 1.05 V ( if I'm not mistaken).

E8xxx series respond very well when overclocked, at higher VTT ( FSB termination voltage ). But like I said, at more then 1,4 V, for an extended time period, it's a death sentence for your chip.

 

[error8]

Originally posted by: wviperw
Tried upping the CPU vcore to the max recommended (1.3625v) and it is still failing out of P95 after 5-10 minutes. I don't get it--I thought E8400s were supposed to reach 9x400 without breaking a sweat?

Increase NB voltage or (MCH) to 1,35 V or something like that.
Increase VTT to around 1,3 V.
Increase cpu v core at 1,3V.

Now it should be stable or almost stable. If it's not, you have to play with those voltages more.

 

[OCGuy]

Transaction Booster: Disable
Cpu Spread Spectrum: Disable

Check all the idiotic options ASUS throws in thier BIOS.

 

[wviperw]

Originally posted by: error8

Originally posted by: wviperw
Tried upping the CPU vcore to the max recommended (1.3625v) and it is still failing out of P95 after 5-10 minutes. I don't get it--I thought E8400s were supposed to reach 9x400 without breaking a sweat?

Increase NB voltage or (MCH) to 1,35 V or something like that.
Increase VTT to around 1,3 V.
Increase cpu v core at 1,3V.

Now it should be stable or almost stable. If it's not, you have to play with those voltages more.

Did exactly that and one core (worker thread #1) ran the large FFT test for 33 minutes and the other core (#2) ran for 8.5 hours. So there still seems to be an issue. Ocguy31 - yep, I've got CPU Spread Spectrum disabled. I didn't see anyway to disable the Transaction Booster and when I tried setting it to manual I couldn't POST.

 

[darthjoe]

Sounds to me like either you have some voltages out of whack, or you just got saddled with a bad chip or mobo. I received my E8400 and P5Q Pro a couple of weeks ago, and the first thing I did was up the FSB to 400, and left all the voltages on auto. The chip didn't even break a sweat.

I'm currently at 9 x 445, with my Vcore at 1.265V and my ram at 1.9V. (E0 stepping on the chip).