How many computers do you use? I use 6 computers from a G3/300 B/W to an 1.25Ghz eMac. I average about 13 hrs per SETI unit, because of the G3. If it wasn't in the mix I could drop it to 11 hrs. Oh, for you PowerBook user running SETI (my's a 667 G4), run a small fan across the PB to keep the internal fan from kicking in. They run hot, I set my PB on rubber erasers (the pink old fashion ones) to gain airflow underneath the PB. Plus the PB doesn't slide around anymore.