Computer Freezes at Random while playing games - Help

System setup:

Mobo: ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard
CPU: Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor
Ram: OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
Video:ASUS EAH4850 TOP/HTDI/512M Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported
HD: Seagate 640gb
PSU: Corsair HX1000W
I/O: Logitech G-15 keyboard and G5 mouse.

WindowsXP Professional (and also tried Windows Vista 64)


The problem is that while playing a game, (Fallout 3, Half-Life 2, WoW) the computer locks up hard seemingly at random. The lights stay on on the mouse and keyboard, but the video freezes and doesn't respond to normal Alt-F4 or Alt-Ctrl-Del type commands. Sometimes I get to play a few hours without problems, and other times it barely makes it into the game before freezing.

Originally, I had this machine set up with Vista and 2 identical Asus 4850's in a crossfire configuration, but it was causing some additional problems (not what I'm looking to solve right now), so I changed to just one card. When this problem persisted, I tried re-installing Vista a few times, I tried different video drivers, I switched between the two cards a number of times, and now I've installed XP, and I'm still having this freezing problem.


Diagnostics so far:
Memtest found no errors.
SeaTools (for the HD) found no errors.
3DMark06 returns normal scores with both cards.
Tried switching PSU's--no change.
Re-sat CPU and re-applied Arctic-Silver and heatsink. (CPU temps are within normal range)
BIOS is the newest version.


I've been trying everything I can think of, but after more than 3 weeks or this I'm out of ideas. What else can I do other than RMA the motherboard?

My wife's computer does this some times when playing City of Heroes and she has a 8800GS and I know for a fact that it is not a temperature problem. Also I have a 4850 and have never had then problem even when my card gets hot.

The only thing I can say is that I scanned my wife's computer with spy boy search and destroy (she downloads a lot of crap) and there was a ton of malware and spyware crap on her computer. After doing that and then removing the crap off of her system it seems to run a lot smoother and so far no freeze ups.

This does sound like a heat issue.

Thanks all for the suggestions. I went ahead and manually changed the fan speed to 65% on the GPU. I was able to play Fallout 3 for an hour, and then suddenly my monitor went black, along with the keyboard and mouse. I had to do a hard reboot to get everything back. During my hour playing Fallout 3 I was playing in windowed mode so I could keep an eye on my GPU temp. The temperature never went above 62 degrees (from what I saw). Is this still too hot? What is the normal temperature range for this type of card?

I was thinking the same thing about the mobo...but I can't figure out a way to test it.

Does anyone know if Asus has some sort of motherboard diagnostic tool I can download to try and identify what the problem is? I have searched their website with no luck.

I had a similar problems recently on my machine, in my case I went into the BIOS and loaded the default settings just to test.

I also upgraded the SATA controller drivers with the latest ones I could find.

I also adjusted the settings for my graphics card's shutdown temp and increased the fan speed.

Since then the problem hasn't returned.

So my lock up issue was either BIOS/SATA Controller/GPU Heat related.

I am unsure which because I did all 3 at the same time and didn't test stability after each change.

I have a strong suspision that the problem was more heat related though.
I think my G-card's GPU recover feature might've been trying to reboot the card and wasn't able to, causing the hang.

Unfortuantely event viewer did not log any of the lock ups.

I have since tweaked the BIOS back to roughly where is was and it's still running fine.

Also, to catch up on suggestions from earlier that I haven't said anything about:

Everything has been re-seated a few times now with consistent temperatures. I've tried a few different versions of Catalyst, and right now I'm back to using the newest one.

I tried the fan speed trick and although it said the speed was higher, it certainly didn't sound any faster.

The HD shouldn't need defragging, because all that's on it is a fresh coat of windows, drivers and a couple games.

Everything is clean still, so dust isn't an issue.

Hopefully that narrows it down a bit. This is the most frustrating experience ever. Thanks ton for all your suggestions so far.

So....after almost 2 months of troubleshooting that included RMA'ing every major component of my system (Motherboard, GPU, PSU, RAM, CPU) the problem has finally been resolved.

I originally had a 750w PSU that obviously wasn't sufficient to run my rig. I figured this out a week after I purchased the system at which time, I purchased the Corsair 1000w PSU. Being that I replaced the PSU early on due to insufficient wattage, it never crossed my mind that the new PSU could actually be defective (especially since all voltages in the BIOS were completely normal)...

Seeing as my symptoms kept pointing to a power supply issue, I bit the bullet and purchased a completely new PSU (different brand, slightly different wattage, completely new unit). Since connecting everything to the new PSU, my computer has run perfectly. It still frustrates me to no end that there was no real way for me to troubleshoot this issue and by dumb luck (and a lot of RMA shipping costs later) I was able to figure it out.

So super, check with your motherboard manufacture first to ensure that your PSU has sufficient wattage to run your system and that your voltages read normal in the BIOS. If you are still experiencing the same issues, I would try and obtaining and completely new power supply to see if that helps.

Thanks all for your help. My nightmare is officially over