TIL, thx.

Ok a bit of trivia out of my chest first [source][1]:

• Para-virtualization is guest being aware to call high level command to hypervisor, rather than calling hardware commands.
• Hardware assisted virtualization: Silicon having instructions to fasten virtualization.

I thought those two were inseperable for some time, turns out they were not.

This seems irrelevant, but VMXNET3 could be paravirtualized but not hardware assisted by virtue (emulated E1000)

While [PVRDMA][2] (allowing shared memory between VMs which have PVRDMA) does similar to what Ilinux bridges does by defauit (IPTABLES forwarding without emulation). Hardware assisted para-virtualization by virtue :D

This has the potential to run above 1Gbit, could you try?

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I’m more familiar with this on linux, but the answer is bridged networking. It must be, as you have surpassed 2.5Gbit theoretical limit of the NIC, and that is before packet overheads. Basically your networking never leaves the “virtual switch” onto real NIC, so it can be a lot faster.

At one instance, I had seen around 35-40Gbps over iperf3 on a beefy PC with around 100GB free RAM and a proper Gen4 NVMe SSD. I think it was due to free RAM being able to accomodate any packet sent/recieved on cache, could not be replicated on prod probably.

So, test again with another LAN-connected machine (2.5Gbps if posaible) and you should be bound by the laws of physics once again ; )