Hi guys 
My PC is often crashing while rendering frames in 3ds Max 2013 x64 with VRay 2.4... Normally if I leave it to render overnight it crashes a few hours in. It just freezes and locks up completely (display frozen at the time of crash). Looking at the logs, often this happens at the start of a new frame - somewhere in between GI (light cache) and main render. It seems to have no relation to how intense the scene is. Sometimes it's crashing on a 1min/frame job, sometimes a 30min/frame
I have tested with just one half of the RAM chips, and with the other half - still doesn't help, so I doubt it's that... (although there could be a faulty chip in both batches, but I doubt it). Also ran memtest86, found no errors. Ram is not maxing out in any case - right now it's rendering and using 5Gb / 32Gb
CPU temps seem normal - around 50° on full load - it has a be-quiet Dark Rock Pro cpu cooler so temps shouldn't be the cause...
Could it be GPU based? I find that option hard to believe as I'm rendering on the CPU, although I do have visual frame buffers (display of what I'm rendering) enabled...
NB: When I first had rendering problems on this PC a few months ago, I got BSODs, but with no sys driver information in the BSOD dumps... Trying everything, I rolled back to an old version of the graphics driver (the one that shipped with the GPU) and it seemed to have stopped it. No way of telling, maybe I just got lucky and had no crashes while I tested. Since then I have updated to the latest drivers from Nvidia's site, so maybe these things are related?
Could it be SATA / AHCI / storage controller related when it tries to read files (some textures used in the renderings are on an external USB 3.0 drive).
I ask this because sometimes I have system freezes (exactly the same) when copying large files (2Gb+) from another (different) external drive via eSATA - using ASMedia 106 eSata controller. It could be related perhaps?
Specs: P9X79 Pro mobo, i7-4960X, 64Gb ram (now using 32Gb), Palit Nvidia Geforce GTX 770 4Gb, Corsair 650W TXM650 PSU
I never have any other problems with the PC - only this...
Please help! Any advice appreciated!

My PC is often crashing while rendering frames in 3ds Max 2013 x64 with VRay 2.4... Normally if I leave it to render overnight it crashes a few hours in. It just freezes and locks up completely (display frozen at the time of crash). Looking at the logs, often this happens at the start of a new frame - somewhere in between GI (light cache) and main render. It seems to have no relation to how intense the scene is. Sometimes it's crashing on a 1min/frame job, sometimes a 30min/frame
I have tested with just one half of the RAM chips, and with the other half - still doesn't help, so I doubt it's that... (although there could be a faulty chip in both batches, but I doubt it). Also ran memtest86, found no errors. Ram is not maxing out in any case - right now it's rendering and using 5Gb / 32Gb
CPU temps seem normal - around 50° on full load - it has a be-quiet Dark Rock Pro cpu cooler so temps shouldn't be the cause...
Could it be GPU based? I find that option hard to believe as I'm rendering on the CPU, although I do have visual frame buffers (display of what I'm rendering) enabled...
NB: When I first had rendering problems on this PC a few months ago, I got BSODs, but with no sys driver information in the BSOD dumps... Trying everything, I rolled back to an old version of the graphics driver (the one that shipped with the GPU) and it seemed to have stopped it. No way of telling, maybe I just got lucky and had no crashes while I tested. Since then I have updated to the latest drivers from Nvidia's site, so maybe these things are related?
Could it be SATA / AHCI / storage controller related when it tries to read files (some textures used in the renderings are on an external USB 3.0 drive).
I ask this because sometimes I have system freezes (exactly the same) when copying large files (2Gb+) from another (different) external drive via eSATA - using ASMedia 106 eSata controller. It could be related perhaps?
Specs: P9X79 Pro mobo, i7-4960X, 64Gb ram (now using 32Gb), Palit Nvidia Geforce GTX 770 4Gb, Corsair 650W TXM650 PSU
I never have any other problems with the PC - only this...
Please help! Any advice appreciated!