Since my servers are really cool (and highly clocked - thanks to freezer cooling, and biiiiig air conditioners) and they are really stable, I can fit about 200 clients and not be near 80% load.. My RAM on each server runs at about 5Gb, crazy I know, but the cooling systems can just clock it up and all, I also share data conections with all my other datacenters, so that helps, the clients data just floats in the middle of cyber space kind of thing, hard to explain unless I could draw a picture..