Summary: I'm super happy to be off a couple small 4GB desktops and onto a real server class computer. CPU has not been the bottleneck for me, but memory has been very limiting. Most of my test machines sit around idle most of the time, but having to pick and choose which ones you have to start and stop has been a pain in my side. But no longer. I now have the following hardware up and running ESXi 4.1.