computer shuts down under load

[neilganon]

CPU: e8400
Motherboard: EP45-UD3P
GFX: 8800 GTS 512
Power supply: 550w corsair


So I've had my computer for a year and a half, and I decided to try my first attempt at overclocking. I got the CPU to 4.05 Ghz (450FSB) with 1.3625 vcore. I ran prime95 for 24 hours and no problems. I used it for a couple days just fine. My temperatures weren't great, around 64-67 during prime95, but I will reseat the hsf when I get a new hdd tomorrow.

Anyways, I brought my computer to a friend's house, and I got bored so I decided to try and overclock my 8800gts. My computer spontaneously shut down when I decided to run p95 as well as realtime hdr demo. My gxf card temp was no more than 79 degrees and my cpu temp was average for the load. I tried it again with no graphics overclock and it happened again. WHAT? I thought the hours of Prime95 indicated it was stable. Then I attempted to play Demigod (cpu still overclocked) and it occurred once more.

My computer is fine now that I have taken the fsb down to normal. Where should I start to troubleshoot? Should I run memtest at the higher fsb? Is this just a preventative setting somewhere that I need to get rid of? Power supply issue? Thanks for any input.

 

[mpilchfamily]

Prime stable doesn't garentee a stable system but its generally a good indicator. I've had many systems that where stable under all stablity testing. Yet F@H would bring the system to it knees and reveal instability.

From the sounds of it you may be exceeding what the PSU as able to handle. You do seam to be getting close. But it could also be as simple as the timings being off.

 

[Matt1970]

Yep, could be power supply is at it's limits. That means you were close to it's limits when not overclocking and are due for an upgrade.

Could also be that you are just pushingthe chip too far. Some chips overclock better than others no matter what you do the voltages and no matter how cool you run them.

 

[Porter21]

Some hardware is just not meant to over-clock. Video cards can be very picky and if you stress them too much you are just shortening the life on them. You said you down-clocked and it still happened? Did you see any artifacts while gaming while it was over-clocked (small white objects that are on the screen).