THreadripper 2990wx not using all cores...

Started by Njen, March 23, 2020, 07:41:51 pm

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Njen

I have two Threadripper 2 2990wx computers (217.6 Ghz each) and a dual Xeon E5-2630 v4 computer (88 Ghz). All three have 64gb of RAM.

When I render a scene I have built on all of the computers, the Threadrippers are averaging between 40% to 60% CPU utilisation, and in some moments, I have seen the utilisation go down to almost 20%. The dual Xeon is always at 100%. I'm using Deadline to render with no UI, and the Threadrippers are completing renders only around 20% faster. I would expect the Threadrippers to be over twice as fast, or is there something I missing?

WAS

March 23, 2020, 07:49:46 pm #1 Last Edit: March 23, 2020, 08:17:16 pm by WAS
I believe this is simply because Terragen isn't currently NUMA aware. I believe the 2990wx is 32core 64 thread. So I believe Terragen is only utilizing 32cores/threads.

Njen

More observation: it looks like in some parts of the image the utilisation is 100%, but in many other parts, it is lower. I have a hunch it might be the v2 cloud layer where it starts to slow down. I will do more tests.

WAS

That could very well be. If some buckets slow down, while other move on through and complete, utilization will drop. Finished buckets won't won't allow working buckets extra help.

Njen

My buckets are small enough where I am getting like 30% utilisation, and the render is only half way done, with at least a third of the image that hasn't started yet rendering. This lack of utilisation is quite worrying.


Njen

Thanks for that link. Based on the information on that page, I found the coreprio utility that was designed to help the NUMA issue, and it helped. Now I'm seeing between 80% - 95% utilisation.

WAS

Quote from: Njen on March 24, 2020, 04:35:23 pmThanks for that link. Based on the information on that page, I found the coreprio utility that was designed to help the NUMA issue, and it helped. Now I'm seeing between 80% - 95% utilisation.

Wow, yeah that's a whooole lot better. Glad you're getting better performance. I still haven't fixed why my servers second Xeon isn't being properly recognized.