WD VelociRaptor 600GB
Like the original WD VelociRaptor, this latest iteration has a unique aesthetic, at least when it is paired to the WD IcePak. While the actual drive conforms to the 2.5" form factor, sliding it into the IcePak essentially transforms it into a 3.5" drive with some additional cooling capabilities, of course...
While the WD Velociraptor HLHX model shown here does conform the standard 3.5" form factor, the actual drive mechanics are housed in a 2.5" HDA drive with a 15mm z-height, similar to the original. The drive itself is mounted in a what is essentially a large heatsink, that keeps the drive cool, while also adapting its connectors to fit in any standard 3.5" bay with backplane.
As you probably know, the WD VelociRaptor is targeted at performance enthusiasts, workstations, and the enterprise. Its 600GB capacity comes from a trio of 200GB platters spinning at 10K RPM within the drive mechanism. Six heads access the platters, and because the platters spin so quickly relative to most other hard drives, and are physically smaller than standard 3.5" drives, the Velociraptor is able to access and transfer data much more quickly than full sized, 3.5" offerings. Complimenting the head and platters is 32MB of data cache and a dual-core processor / controller. In addition, the new WD VelociRaptor also supports a SATA 6Gb/s interface, although it's unlikely any traditional, spinning hard drive will be able to saturate even a SATA 3Gb/s interface any time soon.