I can't speak for development, but I do have a client that has a V-Sphere (ESX4) server cluster that runs WTS. The VM hosts are dual-quad core AMDs at 2.3GHz with 32G RAM. In the cluster, there are 6 servers - 5 W2K8r2 and one W2K3 running Terminal Services. The VM hosts connect to a Cisco 4506 via a 1000bT connection. The workstations are primarily Wyse thin clinets on 100bT connections - some near the limit of the connection length (warehouse environment). With 20-24 users on the system, everything is quite responsive, the TS Guest w/ 4 cores runs between 40-60% load, peaking at times at 100%, but the VM host barely breaks 50%. The 2 nodes in the cluster each are balanced with one heavy use and two light use servers. When examining the switch load during peak processor load times (8:50-9:15 and 10:40-12:15) the switch never exceeds 8%.
RDP is a fairly efficient protocol, and we've done tests for customers with many more thin clients over WAN protocols with good performance.
If anything, I'd be concerned about running multiple XP or Win7 on VMware. Their VDI solution "View" or the competition from Citrix - Xen Desktop - might be a better choice. I do have some clients with multiple XP guests on ESXi 3.5 and the performance is OK, but they use accounting software and Excel/Word/Outlook primarily - not exactly heavy loads. They are also on a 100bT LAN with a 1000bSX link from the ESX server to the switch.
Glenn
_________________________
Actually I
am a Rocket Scientist!
