Let me start by saying that this is more of a computers in general question.

I am trying to runs simulations, and they take way too long in my opinion. I have been monitering the Windows Task Manager in an attempt to determine if I am lacking processing power. However, I am suprised to find that for the majority of the time the CPU usage is around only 40%. The System Idle Process is almost always 70 - 85, while star.exe is about 4 - 8. The perplexing part of this is that for about 15 seconds out of every five or so minutes, the CPU usage jumps to 95+%, with star.exe running at 75 - 85, and the System Idle Process dropping very low. During that time the solver status seems to show significant gains, then it just 'goes back to sleep'

Why doesn't star.exe use the available processing power all the time? I even tried switching the process priority to High, but it didn't seem to change much.

I am running SW 2012 on windows XP.