With the release of ESX 4.1 and vCenter 4.1, VMware has greatly increased the performance of vCenter. I accidentally stumbled upon this VMware document called VMware vCenter Server Performance and Best Practices.
It’s a great read covering benchmark performance differences between vCenter 4.0 and vCenter 4.1, plus a lot of tips and tricks for getting the most out of vCenter. I highly recommend anyone deploying vCenter 4.1 to read the document. It’s really quite enlightening.