Having just grabbed the latest version of VirtualBox as well as the Windows 7 beta, I thought I'd run a benchmark or two of Windows running on top of VirtualBox 2.1.2 with GeekBench.  Overall the performance isn't too shabby, with numbers similar for Windows 7 and XP: Windows 7 Beta: 2697 Windows XP: 2628 Linux Host (Ubuntu 8.10 64-bit): 3306 Host Specs: Intel Core 2 Duo 2.33 GHz, 4 GB RAM The multithreaded LU decomp values seem to be rather suspect, as they well exceed native performance.  Perhaps there's some sort of bug related to timing under virtualized situations?