Windows 10 VM Network Performance - 10gbe

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Hello,

 

I am trying to setup 10gbe throughout my network using Mellanox Connectx-3 in my severs and router. Everything works well on the hosts, but I am struggling to push my Windows 10 guest VMs past 2.5gbps with Iperf3.

 

A bit about my setup, the VMs do not have a network card passed through, I am using a VirtIO network bridge with a VLAN tag. The Windows VM has the latest VirtIO drivers and detects a 10gbe NIC, however my setup seems to be CPU bound and I can't seem to figure out why. I have a Threadripper 2950x, and I see the core assigned to the VM 'emulatorpin' spike to 100% when testing with Iperf. Doesn't seem to be an MTU, flow control, or buffer size issue. Any ideas for trouble are greatly appreciated.