Performance on Quad MacPro

I´ve got a Dual Dualcore 3GHz Macpro. When running apps in XP under Parallels 3, it doesn´t seem to be aware of multiple processors. When XP thinks it is using 100 % of the processor, it only uses about 25 % of Mac´s capacity. Any ideas anyone?

 

That's because Parallels in its current version only lets a guest OS use one core.

 

Any idea i it will in the near future?