Hi, I've had an unusal problem here for last few days. I am running Mandriva 2009.1 32-bit and I have had a couple of random restarts.

One was while browsing with firefox, and the other was playing frets on fire. For whatever reason, there is absolutely nothing in the logs to indicate why the machine rebooted.

The machine generally runs all the time. It can idle for days and days at a time with no problems, and works all the time with no problems until this strange reboot issue.

I thought maybe hardware (heat or psu), but that does not appear to be the case as temps are all normal. The psu is a an antec 650 watt, I can't see that being the problem. The machine is not new and the problems have just now crept up. I can play nexuiz for hours on end with no issues, which is really the only time the machine gets stressed very hard.

So I'm at a complete loss.

As usual with random reboots, check your memory, power supply and temperature (but you seem to have done the last two). Have you done any upgrading recently (especially, videodrivers)? Could be something with mobo, too.

Yes, I ran a memtest after the first one, and all was fine. I think I will start it tonite and let it run all night just to verify.

No, the video driver is just 180.51 that I've been using for a while on my 9800gtx+. Mobo is a really nice Asrock, and I've sorted through the BIOS and don't see any problems. I have an AMD BE processor, but it is not overclocked.

I will test the ram again and see...now that I think about it, there was a power flicker yesterday(the machine was off when that happened), but maybe we could be having some fluctuations there that could be causing it, because I can't find a thing wrong with it. When it randomly rebooted a little while ago, I had the xbox running right next to me though and nothing happened there.

If I were a betting man, I'd bet that you have insufficient voltage driving your memory.

See if you can look up the voltage specs of your memory, and you may need to use your motherboard's BIOS to adjust the voltage upward (instructions vary by model of course) - be sure to not violate the upper limit of your memory.

If you can't find the specs, try to adjust upward - not exceeding 0.10V per adjustment (I believe most BIOS only adjust at 0.05V increments).

Your BIOS *may* be able to tell you if you dropped below a certain power threshold.

See if behavior of the system stabilizes after increasing.

I doubt 650W is insufficient for the system overall, you may just need to tell BIOS to drive more power to the memory. It's possible too that a fan is kicking on when the video card gets too hot, and thus the reboot. If you can provide more detail about what kind of processor, what kind of hard drives, fans, CPU cooling and video card cooling you have going on - that may help someone guess on what the issue is.

If you haven't made any hardware adjustments, it's possible that Firefox is taxing your memory in a way that other processes have not until now.

Also, make sure there are no chassis screws or any metal debris trapped in the case in a place it shouldn't be (like behind the motherboard). Possibly get some compressed air and clean the motherboard if you haven't in a while.

You know, I never even checked it, I just left at whatever the mobo auto-detected. Could very well be the issue here.

I have more than enough cooling, I bought this huge Arctic Cooling thing that looks like a truck radiator, my cpu temp never gets above 50C. I planned to eventually overclock so I bought the cooler ahead of time.

My chip is an AMD BE 2.7ghz Kuma, I think the retail name is Athlon x2 7750.

Everything is clean in there but you may be correct on the memory voltage drop with the video card cooler speeding up. Everything is as clean as can be in there. I'll investigate the memory voltage. Thanks.