KVM: VMXNET3 vs. VirtIO

[TiME]

Which of those two NIC emulators (or paravirtualized network drivers) performs better with high PPS throughput to KVM guests? Google lacks results on this one and it would be interesting to know if anyone benchmarked both with Proxmox and to what kind of conclusion they came. Thanks in advance for your replies.

 

[macday]

VirtIO is not emulated so it should be better than the emulated VMXNET3.

 

[mipsH]

Maybe to late, but (answer from VMware):

VMXNET
Optimized for performance in a virtual machine and has no physical counterpart. Because operating system vendors do not provide built-in drivers for this card, you must install VMware Tools to have a driver for the VMXNET network adapter available.

VMXNET 2 (Enhanced)
Based on the VMXNET adapter but provides high-performance features commonly used on modern networks, such as jumbo frames and hardware offloads. VMXNET 2 (Enhanced) is available only for some guest operating systems on ESX/ ESXi 3.5 and later.

VMXNET 3
A paravirtualized NIC designed for performance. VMXNET 3 offers all the features available in VMXNET 2 and adds several new features, such as multiqueue support (also known as Receive Side Scaling in Windows), IPv6 offloads, and MSI/MSI-X interrupt delivery. VMXNET 3 is not related to VMXNET or VMXNET 2.

It looks that VMXNET3 is not emulated but using some kind of paravirtualization (at least when using on ESXi, not sure how it may work on KVM/QEMU environment --> it may be emulated or?).
On the other side VirtIO s entirely paravirtualized (no emulation at all). It needs another part in the Hypervisor side, which is communicating without QEMU intervention , but directly to Host Linux [Hypervisor] (this is by default implemented on Proxmox VE side in short).

For details about VirtIO architecture (NET, Storage, Baloon, ...), you can take a look at:
Source-1
Source-2