Yes, and actually, on my new quad core with hyperthreading, I'm using 6 threads. The OS thinks I have 8 because of hyperthreading, and somewhat surprisingly, 6 or even 8 run measurably faster than 4. For the RoboRumble, I only run 3 because the integrity matters a lot more there. I up my CPU constant by ~25%, which is about how much slower individual battles run going from 4 to 6. There's some talk and benchmarks on User_talk:Voidious#CPU_benchmark_advice_47 if you want to have a look.