What does Enable single-root I/O virtualization (SR-IOV) do in Hyper-V? Enable single-root I/O virtualization (SR-IOV) is a Hyper-V External Virtual Switch setting that offloads to the emulated hardware, instead of virtualising it in Hyper-V as a software device (not physical).
There can be some performance advantages of enabling single-root I/O virtualization, but SR-IOV will probably make your network go slower because:
Emulated devices requires lots of Hypervisor intercepts for every single I/O
Operations can’t use shared memory access, which is faster
Emulated devices require operations that are based on the hardware emulated functionality, whilst software devices can be programmed based on the required functionality of the software and are therefore faster
There’s not need to transition through layers of the hypervisor to send commands with software devices, so conversely single-root I/O virtualization is slower