In general Virtual Machine Queues are often disabled on Hyper-V hosts, to solve network slowness. However, if we go here:
HKLM\SYSTEM\CurrentControlSet\Services\VMSMP\Parameters
and add DWORD BelowTenGigVmqEnabled
and set it to 1, or TenGigVmqEnabled
for 10G, we can enable Virtual Machine Queues and get great speed indeed.