What may cause this ?

[vm1990]

It's a crash, so don't do things that make your graphic card crash... buy better hardware, don't overdrive it, don't overheat it, get your graphics card manufacturer to make better drivers...

Obviously the reasons can be multiple. By hardware I guess you meant risers and accessories? The main hardware is pretty much standard (280xs, mobo gigabyte etc etc). As for overdriving, well all is stock. Heat, well cards are running at 70-71C. Perhaps the drivers would be my last resort by reinstalling, but I can only rely on those who produce it...AMD...

Could the crash also simply be a defective GPU?

I'd test each card on its own 1 at a time and mine with them for at least 30mins. This will find if there's a weak or defective card. If it finds nothing and all the cards check out its more than likely a bad psu or failing pci-e adapters on the motherboards.

[polanskiman]

It's a crash, so don't do things that make your graphic card crash... buy better hardware, don't overdrive it, don't overheat it, get your graphics card manufacturer to make better drivers...

Obviously the reasons can be multiple. By hardware I guess you meant risers and accessories? The main hardware is pretty much standard (280xs, mobo gigabyte etc etc). As for overdriving, well all is stock. Heat, well cards are running at 70-71C. Perhaps the drivers would be my last resort by reinstalling, but I can only rely on those who produce it...AMD...

Could the crash also simply be a defective GPU?

I'd test each card on its own 1 at a time and mine with them for at least 30mins. This will find if there's a weak or defective card. If it finds nothing and all the cards check out its more than likely a bad psu or failing pci-e adapters on the motherboards.

Thanks. It really seems that it's the GPU that has a problem. The rig kept crashing quite often. I took that GPU out and all seems to be working fine now. I tried plugging it back several times and problems kept happening again and again, and often even at boot time. Tried changing the riser too, to no avail.

[wunkbone]

Try different setting for your GPU that hang, sometimes lower clock helps..

[polanskiman]

Try different setting for your GPU that hang, sometimes lower clock helps..

I had tried that before. I even brought the GPU to its default values. Those hangs seemed more of a hardware problem than anything else as the whole rig froze each time and the only way to recover was by doing a hard reset.

The rig has now been running continuously without that particular GPU for the past 12 hours without hangs.

[cryptom00n5]

Anyone find a solution to this problem?