8800 GT -> 5 clients
Core 2 Duo 2.66 ghz -> 4 clients
10,000 RPM HD -> 3 clients perhaps, depends on the HDD. A regular HDD(7200rpm) can run 2 clients.
2 Gigs DDR2 -> 2 or 3 clients. depending on how much other software you run in the background

So, overall I'm guessing that you can run 2 or 3 clients smoothly.