New core i5 build instability

[bishyaler]

even though memtest and prime95 run without issues, win 7 x64 randomly bluescreens and apps crash. this usually happens at low load, idling, surfing web or syncing itunes. the loadout is: intel dp55wb motherboard, corsair 4gb ddr3 1300, 8800GTS 640mb, wd caviar black 1tb, enermax 405w PSU. i am running this at stock and my temps at load are about 50c. any advice?

 

[Flatulenzia]

405W seems dangerously, dangerously low for that build...any possibility of popping a more powerful PSU in temporarily (or permanently!)? Barring that, you might want to run a CHKDSK.

 

[bishyaler]

i may add a bigger PSU, but you would think prime95 would crash or bsod if it was undervolting. i run a shuttle with a 400w psu and have a c2d e8400 and gtx260 with no issues. ive ran chkdsk, everything comes up clean.

 

[shortstuff_mt]

Did you manually set the RAM speed/timings/voltage to the recommended specs in the BIOS? I've seen systems with the RAM voltage set too low pass Memtest86+ but BSOD during everyday use. Memtest86+ is good at finding faulty RAM, but not that great at detecting incorrect RAM settings.

 

[bishyaler]

Did you manually set the RAM speed/timings/voltage to the recommended specs in the BIOS? I've seen systems with the RAM voltage set too low pass Memtest86+ but BSOD during everyday use. Memtest86+ is good at finding faulty RAM, but not that great at detecting incorrect RAM settings.

The corsair sticks are rated at 9-9-9-24 2T 1.5v. ive tried using auto config and manually setting. cpu-z 667mhz JEDEC indicates 9-10-10-25 timings which i thought was odd since the bios does not use these on auto. not to mention corsair states 9-9-9-24. even setting these timings loose, the instability persists. on an unrelated note, im running ahci if anyone knows of any known issues with that? the stress tests working is what throws me, prime95, running world of warcraft, downloading win updates simultaneously is fine, but surf the web or drop music into itunes and it BSODs. or random services will crash when idle.

 

[bishyaler]

For anyone this might help (including me), the problem doesn't seem to be the ram timings. It appears that when when the processor is idle, it is being undervolted, causing a BSOD. Disabling Intel Speedstep and C1 State in the bios fixes the issue, but obviously isn't an ideal situation (no Intel Turbo mode, no power savings).
I built a 2nd system with identical specs except this time I used a 750w Corsair power supply. The 2nd system experiences the same issue. I've updated the bios on both boards, which appeared to fix the Speedstep/C1 State issue on the original system with 405w PSU, but not the new system with the 750w PSU. I'll try to reflash the new system now and report on what I find.

 

[bishyaler]

Update: Flashing the bios didn't fix the issue on either machine. Both are still BSODing when idle. Running both with Speedstep/C1 disabled and forwarded an issue up to Intel Tech support.

 

[onesmallstep]

I had exactly the same freezing / crashing symptoms at idle

Here's my spec:
GA-P55-UD3
4GB PC3-10666 (1333MHz) Corsair CM3X2G 1333C9D
i5 750
Corsair 450W
ATI HD4870
Windows7 Home Premium 64bit
CoolerMaster CM690

Here's what I did to get Prime 95 stable for 3 hours (Max Temp at Full load=39 deg):
BIOS 6a (Beta!)
Fenrir Titan Cooler (would only fit by reversing 180deg, reversing air flow on rear fan and adding 2 exhaust fans on top of case)
Disabled C1E/C3/C6/C7/EIST/TurboBoost
Set base clock to 166
CPU multiplier to x19 = 3.154GHz
RAM multiplier to x8 = 1328 MHz

CPU Voltage to 1.625v (EEK!!!)
RAM Voltage to 1.64v

Result is stable and cool and fast