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cap089

unRAID crashes after GPU Passthrough to Windows KVM

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@metathiasOk, I updated the CPU Pinning, see the screenshot. Now nothing "blocks" Core 0 and his HT twin.CPU_Pinning.thumb.png.213021521270cf02425076e53f3c935a.png

 

But the Overhead is still there. As you can see:

overhead_KVM.thumb.png.f206432cfa942a72427e3438e30a239e.png

 

I also tested it with just 6 cores. My idea was because of the Ryzen 3900X which is actually 2 x 6 cores on two dies, maybe thats has an impact. But it doesn't matter, with just 6 cores/ 12 threads the overhead is also present.

After the restarts of the VM I also recognized that the impact of the overhead seems to be variable, because after the restart and testing in a game, the lag was not noticeable but the overhead was still there..

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@cap089 What do you mean by "overhead"?

30 minutes ago, cap089 said:

But the Overhead is still there. As you can see:

 

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Is this not the right term to describe this? The core utilization is higher than the Windows VM actually need. I know the refresh intervall of the task manager and the CPU load overview in unRAIDs WebUI is not perfectly syncronized but a difference up to 30% seems quite high and it get noticeable in games.

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Honestly i have never thought to compare the two. Not sure what good it would do. Resource utilization meters. On both Unraid, And Task manager in the VM. Essentially just take a snapshot of the CPU current usage at the exact moment in time it was captured. It practically impossible to make sure they took a sample at the exact same moment in time. Therefore it highly unlikely their going to agree from one interval to the next about exactly how much that thread got utilized since the last interval.

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Hmm. But when I check the graphs in the WebUI over time, I have constantly load on the first core from about 20% and on the second about 15%. And 3-5% on the other threads. And this during Windows is in idle - just chatting or watching Netflix.

And of course when the VM is shutdown or in sleep mode the load is gone, so its connected to the VM and nothing else..

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Perfectly normal for me. First core of my VM shows about the same with nothing running (15-20%). Again i would ignore this metric. Focus on real world benchmarks. And gameplay.

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Okay.. Then I keep an eye on this and hope that the lag does not appear anymore.

 

EDIT: Now I know how to reproduce the lag. Everytime after the VM was in sleep mode I got the lag. Really annoying -.-

Is there a chance that this will be fixed by sooner updates of unRAID? Otherwise the VM has to run the whole time and then I just can switch to baremetal Windows and run everything from this...

Edited by cap089

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Ahh. Hmm. I always turn off the power features of a VM. I just put it high performance mode. Seeing as how the VM has no real control over power functions anyway. And pulling a VM out of sleep can be a pain. If you want to play with power saving features. Your gonna need to do what you can on the unraid side.  I would keep in mind. that unraid is after all a server and thus meant to run 24/7.

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Ok, I switched to the AMD high performance mode but it did not change the behaviour after standby.

And yes I know that the server is everytime running but I thought I can save some energy when the Windows KVM is in standby when I am acutally not sitting in front of the PC. Especially when 3/4 of the amount of cores and the graphics card are "switched off" in standby. But actually I did not measured if it make a big difference, yet.

 

EDIT: As a workaround I can just use the hibernate mode instead of "normal" standby. Because of the lack of Windows to keep application windows etc. in place, I don't want to restart the VM everytime.

With hibernate its behaves like "switched off" - meaning no lag - and Windows no longer annoy me :D

Edited by cap089

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Final Update: I just tested Battlefield V the last days and here everything seems to work.. But yesterday and today I tested CPU intensive games like Hunt and PUBG . Regardless if the VM was in Standby/ hibernate or just restarted, the overhead has a massive impact. The mouse is slow and laggy and the CPU is a bottleneck, so the graphics card can not fully boost...

So I am done with unRAID there are too much uncertainties with this. I will now run everything within Windows.

Anyway thanks for the support in this forum! :)

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