Windows VM network speed dropping over time

SoulSauce

New Member
Nov 23, 2024
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0
1
I have a persistent issue where a windows VM (only one I know of with this issue) has a persistent problem of the network speed dropping after a period of time.

I'm using VirtIO with multiqueue and I get 10Gb speeds as expected, but after a few hours, the speed seems to drop to become capped at ~600Mbps. The odd thing is it works perfectly well for hours before doing this. It always returns to ~600Mbps over time. When I make a change to the adapter in the Proxmox UI, such as switch to Intel E1000 and then back to VirtIO or change MTU then back, etc., it goes back to 10Gb for several hours. It seems to be isolated on the VM and changing networking setting on the VM instantly fixes it, but it's only temporary.

Is this a known issue? I can't find any posts describing this. I find plenty of posts where people explain poor speeds without using VirtIO and multiqueue, but I don't see posts of people describing this specific behavior.

Does anyone have an idea of what I should look at to stop this? I'm thinking of making a script to reinitialize the adapter or something as a work around...
 

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