Shot of my ESXi 3.5 cluster. Two HP DL 360 G3’s. 4G RAM each, dual CPUs. Yes, those are Diet Coke cans. Can never have enough ventilation/air space.
Shot of my ESXi 5 cluster. Three Dell XPS 720’s. 8G RAM, quad core each. Each box is connected to a 24-port GigE switch with 4 GigE ports per server.
Shared storage. A nice little QNap TS-259 Pro+. 2 TB raw space mirrored (RAID-1). iSCSI over GigE to all 4 servers.
Screen shot of vCenter.