An overclocked quad core with four threads can generate 15-20,000 points/day. A quad core with eight threads (i7-920, i7-930) can get 30-35,000. A hexa core with 12 threads can do 40-50,000 points/day.
Do you happen to know what the University of Illinois at Urbana-Champaign is running? Their listed as 6 members and are now generating about the same amount of points per day as XS team!