Cycles CPU rendering keeps crashing 2.79 / 2.80

I built a new PC:

  • AMD Ryzen 7 2700X Water cooled
  • Corsair Vengeance RGB (2x, 16GB, DDR4-3200)
  • MSI X470 Gaming Pro Carbon
  • Geforce GTX 1070 Ti

PC is running everything very smoothly, except: Blender!

For some reason, it keeps crashing and crashing at random moments, but only when I use CPU rendering. For comparison I was using the BMW benchmark scene.

I’m rendering with CUDA and GPU/CPU combined. Just GPU rendering is perfectly fine and does more than 20 frames at about 2minutes per frame. Combined rendering is about 1:30 minutes. But every time I put the CPU to use (alone or with GPU) it crashes anywhere from 1st to 10th frame. By crash I mean that it just drops me out of blender with a quick black screen, but without any error messages. Debug mode just always stops at CPU rendering.

When I do the same in Linux, the whole PC freezes on me. It seems, that it gets better, when I put my DDR’s at 2133 Mhz, but I could be wrong and it still crashes anyway.

Under windows the tile animation when rendering seems to freeze some times, also the whole computer freezes, even with just web browsing.

Now what I just did find out, after setting “threads” to for example 10 instead of 16 (disable auto mode), everything seems to be running smoother. Even the render times go down to like 1:20 minutes.

I don’t know yet, if that is the solution, but it seems a lot better for now.

By the way, Cinebench R20 has no problems at all.