Western Digital 640GB - Twice the Platters, Twice the Fun
 

Western Digital's emphasis on recent product releases has been the consumer oriented GreenPower family of products. That all changed last month with the release of the Caviar SE16 320GB drives featuring their new 320GB per-platter technology. We previewed this drive and came away impressed by its excellent thermals, power management, and acoustics but depressed by performance that was not any better than previous generation drives featuring 166GB~200GB per-platter designs. We have an answer to our performance-induced depression but that will have to wait for page two.

The second drive from WD to utilize their new 320GB per-platter technology is the Caviar SE16 640GB WD6400AAKS. This areal density places WD once again in competition with Samsung's F1 lineup featuring 334GB per-platter sizes with similar thermal, acoustic, and power envelope specifications. However, Western Digital decided to branch off in a new direction with a 640GB capacity instead of sticking with the tried and true 500GB and 750GB offerings from their competitors.

http://www.anandtech.com/storage/showdoc.aspx?i=3269

some people may actually like the idea of this... i'm planning on buing one of the 750gb green drives in fact.