Computer powers off under Prime95/heavy gaming.. already replaced PSU.

R

Rizen

[H]F Junkie
Joined
Jul 16, 2000
Messages
9,487
Hello,

Recently I noticed that under certain high load situations, like playing BF3 or running Prime95, my computer would hard reboot - no BSOD, no errors, just shut off and then turn back on. I understand this is typically a power supply issue. I was using a BFG EX-Series 1000w PSU, which should be more than adequate for my computer. Nevertheless it was a few years old, so I replaced it with a brand new XFX Black Series 1250w PSU. I am still encountering the same problem.

The powering off can take anywhere from 10-30 minutes to happen. It seems to be slightly longer on the 1250w PSU now than it took on the 1000w.

Other things I have tried:

Changing power outlets
Unplugging the PC from the older APC unit it's connected to (~3 years old)
Upgrading the BIOS to the newest version
Reseating all of the power cables

My CPU doesn't go over 70C in games or 85C in Prime95, as it is watercooled. All temperature warnings are shut off in the BIOS. The system will run less intensive apps like Skyrim fine, and I can idle/browse the internet all day with no issues.

Any other ideas? Is the motherboard the main culprit at this point? My full specs are in my signature.
 
Have you tried running stock and priming it? Perform MemTest on each individual stick?
 
I'm lowering the clocks now and Priming. Will update with the results.
 
None of the caps that I can see look to be leaking, split or bulging.
 
XenIneX said:
This is what years at 85C @ 1.4v gets you. Downclock and reduce voltage.
Click to expand...
I understand it reduces the lifespan of the CPU. That's a risk I am willing to take :) I really should upgrade to LGA2011 anyways given that I have PCI-E 3.0 video cards and several SATA3 SSDs, but I don't have the money to drop $1k on a new CPU, motherboard and waterblock right at the moment.

Also, I should mention that 85C was seen only under Prime95 or LinX, which I only ran a few times to verify stability. Under BF3 I never see temps over 70-75C.

I am priming at stock speeds/voltages now.. so far about 25 minutes in and no issues. Will report back in a little while.
 
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Update: I primed the system at 3350MHz, 1.2v for over an hour with no hard reboots. It seems the problem is specific to high overclocks.

I guess I can run the system like this until I can afford a new motherboard/CPU combo. What is more likely the culprit here? The CPU or the motherboard?
 
CPU.

Take it down to 4ghz @ 1.3something volts and it should be okay. Somewhere that Prime95 doesn't exceed 75C, though lower is better.
 
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Running 4GHz (200x20) at 1.275vcore 1.3v QPI right now, will see if it holds. Thanks for the advice. I am trying to wait for IvyBridge-E or Haswell before upgrading, so just need this to last until then.
 
Did two hours of Prime95 large FFT at 4.0GHz, 200x20 @ 1.275v. No errors, no reboots. Max temp 68C. Looks like 1.4v is no longer in the cards, but the CPU still is pretty good. Thanks for the advice guys.
 
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