My testing of Virtual Machine to Virtual Machine throughput demonstrated that with minimal tuning, considerable throughput can be obtained between virtual machines running on the same Hypervisor.

Clearly, the next step was to test throughput between Hypervisors… I had planned on running some initial tests, then based on the results, going “all out” and configuring SR-IOV as needed to obtain as close to wire speed as possible, but initial testing generated some great results…

Just some weekend testing with two Windows 2012 R2 VM’s on the same Hypervisor and tests to see what throughput can be generated using the Microsoft NTttcp utility…

These are truly science experiments given there is no application that runs with a single IP stream between internal VM’s (such as App to DB) or to external users… By definition, every user connection would be a unique IP stream.

Overall, pretty straight forward to achieve multi gigabit performance out of the box and with more simultaneous streams, the aggregate bandwidth could easily exceed physical wire speed of the server.

The 64KB window is also a worst case scenario and certainly bigger window sizes can assist in improve throughput…