If we refer to the current version which is ESX 3.5 u3, the maximum number of Vcpu per ESX server is 192 per ESX Servers. Personally, I think the number of Vcpu per ESX servers is too minimal. Imagine if we do run a servers with 4 or 8 physical CPU sockets and we consolidate 40 : 1 Physical server in our virtualization environment, we will hit to the bottleneck on maximum numbers of Vcpu per ESX servers but not due to the CPU consumption.I hope VMWare should revise the configuration to greater number or 256 Vcpu per ESX servers.

The reason of virtualizing today, is really not about sacrifice performance. In our environment, we have most VMs running with 4 Vcpu as the result of customer compare VM to Physical Servers to ensure the performance is sustainable or improve when they switch to VM. When the VM itself is idle or less busy, it will not consume too much resources on the Physical CPU cores. Next release of ESX will go for 8Vcpu per VM. The number of Vcpu been assigned to the VMs which require extra CPU resources will increase too.

Updated: Configuration Maximums for VMware Infrastructure 3 – Number of Virtual CPU = 192