We're experiencing extremely poor performance running on a Windows Virtual Machine under XenServer and VMWare.
Server FPS with 50 Players under Virtual Windows with 8 vCPUs and full CPU priority = Average 18fps
Server FPS with 50 Players under standard/dedicated Windows on the same server hardware = Average 35fps
CPU: Intel Xeon E3-1245v2 at 4.0 GHz
For reference; we do not face this issue in ARMA 2.
I'm able to provide multiple E3-1245v2 servers for testing/development purposes if required.