Random pc shutdown/restart

[tim_bethany]

Hi
I have just finished my build from getting lots of help from here

My problem is that my pc will randomly turn its self off? it first started happening when not doing anything, so I reduced the overclocking from 3800 to 3700 and now it only does it when in a game like COD 6 and alien vs predator these are running on almost full by the way.

Do u think I should reduce the multiplier even more or should I increase the voltage?
or is it nothing to do with this?

I finally settled on the following:

Case: Antec 902
Motherboard: Gigabyte GA-MA790X-UD3P
PSU: Antec EarthWatts 750W Modular PSU - 80plus Certified 9x SATA 4x PCI-E
CPU: AMD Phenom II x4 955, OC'd to 3.7
RAM: 4 x Corsair XMS2 CM2X1024-6400
GPU: ATI HD 3850 256mb PCI-e
HDD: Seagate Barracuda 7200.9 160 GB
HDD: SAMSUNG HD103SJ 1TB
Windows 7 64bit

That’s the rig

I’ve been looking online for the problem seems alot of people have it and the most mention problem is the PSU did a calculator thing and I have more than enough power, but I did check the voltages and the +3.3 V was at 3.30 V all the time BUT, the +12 V would stay at 12.32 V for a few seconds then flick to 12.25 V which I don’t know if that’s bad or not.

Also my temperatures are fine if anything they might be a bit low:
HDD's @ 24°C
CPU @ 36°C & load @ around 50-60°C
Motherboard @ 28°C
GPU @ 34°C
However my gpu does get to 75°C on load but apparently that’s fine.

NOTE: I just checked my CPU spec while typing this and its being a bit weird and the CPU FSB, HT clock, North Bridge clock keep changing? Anything from 188 to 200.8 (stock is 200) is this normal?

 

[brett1042002]

Windows 7 has an option checked by default to reboot or shutdown when a serious error occurs. You can disable this option to view the BSOD for detailed information. It could be due to bad RAM (run memtest86+), or an unstable OC (go back to stock settings and see how it performs). Good luck.

EDIT: The FSB, HT, voltage decreases/increases are normal when Cool N' Quiet is enabled. When the system is at idle, the CPU is underclocked automatically to conserve power.

 

[Guest]

FSB change is normal if you have EIST (or speedstep I think)for Intel and its probably triggered by Cool n' quiet from AMD

Its dynamic fsb scaling for saving power, and changes depending on system load.

that's why your seeing the FSB scale change on the fly.

Regarding shutdowns, I assume its a heating issue somewhere especially if you are saying it happens when you load the system while playing games (considering it happens with GPU intensive software)

My 2 cents, hope this helps.

 

[tim_bethany]

ok thanks im almost certian its not heating cos its very cool and i have just updated my bios so i will see how it goes also will look into the win 7 thing cos bsod would be more helpfull
thanks