By configuring 4 VFs to each port (8 VFs for the two dual-port nic) it means that each VF shares one or more physical resources of the physical-device, such as a memory & a network port, with the PF and the other VFs on the device. so basically, if all VFs are in Active, then you will have more or less equal performance on each and one of the VFs
NO. A vf does not interfere with the other vf for the reason I said above (sharing resources…)
If you created 4 VFs per 10GBp/s port it is indeed sharing “equal parts” of 10Gbps (assuming all are active)