I thought I would raise this again, because last time I mentioned it, it was as a comment to another thread and possibly more of a serious issue. The Parallels hypervisor performance is extremely poor on systems with high core counts where a large number are assigned to the VM. A quick Geekbench test from the latest build gives the following results: That said, the parallels hypervisor is still terrible compare to the Apple hypervisor. Geek bench scores with 24 VM cores: Apple: Single Core 1010 Multicore 11648 Parallels: Single Core 1109 Multicore: 3575 It's quite a shocking disparity. In terms of time, it took just over two minutes to complete the tests using the Apple hypervisor. The Parallels over fifteen. In other basic tests I've done, the Parallels hypervisor only seem to scale well to about 8-10 virtual cores.