I think this issue has been addressed before. I have a Macbook Air and have noticed at time my CPU usage spikes with Parallels running and Windows 7 Pro is the guest OS. At times the Mac OS Activity monitor shows pr_vm_app at 100%. It causes my fan on the Macbook Air to dramatically speed up. After a while it manages to correct itself and the MBA fan quiets down. I have tried a lot of typical solutions like reinstalling Parallel tools and even reinstalling the OS. Disabling 3D and adjusting RAM. I have yet to find any issue with the guest OS causing the high CPU usage and I do believe that thread (prl_vm_app) pertains more to Parallels itself. If anyone has any ideals, please make some comments. I've considered several times of just giving up on Parallels because I do not want to shorten the life of my MBA with it getting to hot.
