Virtual Hard Disk Performance (VHD) in 2008 / R2 / 7
Interesting doc published this week on the performance of vhd files mounted natively vs raw disk, etc..
Give it a look here: https://download.microsoft.com/download/0/7/7/0778C0BB-5281-4390-92CD-EC138A18F2F9/WS08_R2_VHD_Performance_WhitePaper.docx