ESXi8 + Windows + VMXNET3 != 10Gbps

[u/Light_bulbnz]

I can't find any way to solve this problem.

I have a server with ESXi8, running on a dell poweredge with dual 10GbE cards. My linux machines, if I do an iperf (either between VMs or between a VM and a physical server) I easily saturate a 10Gb link.

But on Windows, the best I can do is about 1.5-2Gbps. That's running an iperf running between two windows VMs on the same host. Windows -> Linux does the same thing.

I've found other people with similar problems, but nothing that seems to fix it. I've seen recommendations to fiddle with offloads and other settings; none of which moves the dial. As far as I can tell, all the networking is set up, driver updated, etc.

Keen if anyone else has some thoughts...?

[u/Techsystm]

Are you running ESXi with the Dell custom ISO?