Hardware Accelerated BitLocker Encryption@ 2013/04/11
The bad news has been that relying on OS driven filesystem encryption always meant the use of software encryption on top of your drive’s native encryption. This was particularly a problem on SandForce based drives, where full disk encryption basically ruined any of the performance advantages of the controller’s native compression/de-dupe (you can’t further reduce encrypted data). Other drives suffered (just not as much) due to the added overhead from having to leverage the host CPU to encrypt all data before writing it to disk. There’s also the fact that if you encrypt your entire drive (free space included), the drive ends up looking like a completely full drive - which has performance implications of its own. This was the world that existed with BitLocker under Windows 7 and FileVault under OS X.