Rendering Problems

[johnwright22]

We have a new computer, this is the first time we have tried a threadripper chip as our render. We are having issues renedering with it. Not all of the buckets are rendering, we get a few buckets that look like a preview. See attached teapot. If we render any of the scenes on another machine it works fine, but on this one machine it always leaves buckets unfinished.

[hermit.crab]

Does this happen on any scene on that specific machine? Does it happen every time or on a random basis? What's the whole model name of the CPU? Have you overclocked your CPU?

[johnwright22]

It happens on every scene on that machine.
It is a threadripper 2900wx and it is not overclocked.

[hermit.crab]

Another thing, are the wrong buckets always in the same place?

[johnwright22]

No, each time they are in different spots

[hermit.crab]

We suspect that it may be a faulty hardware issue. A few more things to test:

1. Does the issue occur when rendering with V-Ray Standalone or V-Ray Benchmark?
2. Does the issue occur when rendering with other renderers?
3. Check if the CPU is overheating.
4. Are there any errors in the log?
5. Try checking if the issue is caused by a particular thread with the "Set Affinity" option in the Details tab of the Windows Task Manager. Run some tests, i.e. with half of the threads, and so on.
6. Try running another benchmark software to test the CPU and RAM (i.e Prime95)

[johnwright22]

1. Standalone
2. Scanline renders fine
3. no it is not overheating
4. See attached file
5. Set Affinity doesnt work in windows 10, just resets back before each rendering. Can you help me with how to do that.
6. Already tested with Prime95, no problems

[hermit.crab]

There seems to be a warning in the provided log, which may need investigating. Could you send the scene from which the log was created (either attach it here or send it to support@chaosgroup.com)?
Regarding the Set Affinity, I tested it on Win10 also and it seemed to work fine. I simply changed the affinity of the '3dsmax.exe' before rendering without restarting 3ds Max (screen).

[hermit.crab]

Thanks for the provided scene. The "invalid light cache sample" warning is not present when testing on your scene, neither are the strange buckets. Just for testing's sake, could you try to render the scene with Brute Force/Brute Force or without GI to see if these buckets are present? I presume you've already reinstalled V-Ray, try doing so if you haven't. Also, try disabling any third-party plugins. Otherwise, we may need to arrange a remote session to continue the investigation.

[hermit.crab]

We could not reproduce the wrong buckets nor the invalid light cache error on a Threadripper 3970X. I would suggest continuing testing the hardware of your system (maybe try running a MemTest86 stress test to see if it's a memory-related issue). Please, provide feedback with your testing results.