nlash Posted August 29, 2019 Share Posted August 29, 2019 Using a Ryzen 2700x. I've tried various groupings of cores (always along with the grouped HT pair) and anything over two cores causes the entire vm (mouse included) to massively stutter every couple of seconds. I've tried everything under the sun and this is the only way I can get a stutter-free Windows 10 VM. Quote Link to comment
Squid Posted September 14, 2019 Share Posted September 14, 2019 No where near an expert, or even knowledgeable but, from reading the threads here is there a major latency problem because of NUMA pairing? (or something like that). Maybe google "unraid numa" Quote Link to comment
nlash Posted September 14, 2019 Author Share Posted September 14, 2019 For some reason I thought Ryzen chips only had the one node or whatever. Quote Link to comment
jbartlett Posted September 15, 2019 Share Posted September 15, 2019 Check out the spaceinvaderone videos on installing lstopo which will give you a visual representation of your numa nodes, the CPU's & PCIe slots tied to them. This will help you pick your CPU assignments. Quote Link to comment
nlash Posted September 17, 2019 Author Share Posted September 17, 2019 Here's my lstopo output. Not exactly sure how to interpret it since it's a different type of CPU than spaceinvaderone's example. Quote Link to comment
nlash Posted October 1, 2019 Author Share Posted October 1, 2019 Anyone out there with some insight? Quote Link to comment
thenonsense Posted October 29, 2019 Share Posted October 29, 2019 Not sure if this was ever resolved, what cores are you typically passing through? Quote Link to comment
nlash Posted December 4, 2019 Author Share Posted December 4, 2019 No, wasn't resolved. What cores I use doesn't seem to matter—adding more than 3 cores causes unfixable stutters. If I add a 4th, then reduce it back to 3, the stutters stay and can't be fixed. Quote Link to comment
JesterEE Posted December 25, 2019 Share Posted December 25, 2019 I saw something like this today. I tried it many times with little tweaks to the configs because I didn't believe what I was seeing, but you are right this is a thing! I have a Ryzen 7 3800X on a ASUS ROG Strix x570-E board with bios 1405 AGESA 1.0.0.4 Patch B, and I saw significant input lag/stutter (i.e. mouse cursor skipping) when isolating CPUs from different CCXs. I didn't even have to use them in the VM ... just isolating CPU cores in Unraid from different CCXs and starting the VM using cores for 1 CCX (or both) was enough to cause the lag. Here is my CPU architecture which is similar to yours. I passed the 2nd CCX (cores 4-7 & 12-15) and a HT core from the 1st CCX (cores 3 & 11) leaving the rest of the 1st CCX for Unraid during my testing. This may be more complicated of an issue for me as I am having other VM stuttering issues which I posted about here. But I wanted to validate your finding! You're not crazy! -JesterEE Quote Link to comment
nlash Posted December 27, 2019 Author Share Posted December 27, 2019 It's good to know I'm not crazy. Just to add another data point...I currently have cores 3, 5, and 7 isolated for my Windows VM. If I'm reading my architecture correctly, that's across two CCXs. It runs perfect. If I add another core—any core—guaranteed stuttering. My emulator is on core 0. Luckily this is only a gaming VM, so three cores is enough, but I've never been able to solve it. My MacOS VM that uses those cores plus core 1 runs like butter. Quote Link to comment
joggs Posted January 8, 2021 Share Posted January 8, 2021 (edited) Very interesting! I have exactly the same problem. I could not add more than 2 cores before the stuttering began in Windows, but I did not test the 3,5,7 combo, which actually works, so now I have 3 working cores, so thank you for that. Also, MacOS runs as butter with more cores for me as well. Any new findings in this matter, as the last post is over a year old? Edited January 8, 2021 by joggs Quote Link to comment
nlash Posted March 16, 2021 Author Share Posted March 16, 2021 Quote On 1/8/2021 at 10:50 AM, joggs said: Very interesting! I have exactly the same problem. I could not add more than 2 cores before the stuttering began in Windows, but I did not test the 3,5,7 combo, which actually works, so now I have 3 working cores, so thank you for that. Also, MacOS runs as butter with more cores for me as well. Any new findings in this matter, as the last post is over a year old? I've actually since upgraded to a 3900x. But, before the upgrade the problem went away and I was able to add 4 cores. I don't know what updated or what changed, but something fixed it. I currently have 8 cores passed to both VMs (not simultaneously) and everything runs fine. No clue what changed. Quote Link to comment
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