Does anyone have information about this? Or should I just test? I began thinking about this last night when my computer started to feel sluggish. I was using BeOS, Seti@Home running in background, listening to music, copying files when I realized that windows are resizing & moving slower than usual. Then I checked my CPU temperature - 82C! Looked into the case - CPU fan had shut down. Now if I had a realtime CPU speed monitor, I could make a chart about how much temperature affects speed. I'd say it was something like 200-300 MHz, it felt like that.