Unless you are talking the PGMusic Audiophile version, which uses full .wav format RealtRacks and RealDrums, you are talking about .wma compressed files anyway. The Audiophile version does ship on a 7200rpm drive.

Streaming from USB is not an issue, besides that, there really is no realtime streaming from the drive, RealTracks are created and run from the Temp area of your C drive.

--Mac