I have a complex video mixer patch that runs smoothly (25FPS at least) on MAC.

I would like to use a PC to run it, the thing is that on the PC it has a very low performance, only one of the 4 cores seems to be processing, and the overall CPU usage is 22%.

Is there anything I can do to solve this?

PC specs: XP Pro, Quadcore @2.83 Ghz, 4GB ram, ATI Radeon HD 4800

Thanx in advance