The Raptor X, model WD1500AHFD, reflects the third generation of the Raptor series. This model upgrades the Raptor to a 150GB capacity, a 16MB cache, and it throws in NCQ as well. The 150GB Raptor is also available as the WD1500ADHFD, which has the same specifications but lacks the clear window on top which the Raptor X is known for. After a 36GB and 74GB offerings, the Raptor has finally been made available in a drive large enough to be used for almost any application, not just specialty purposes. Western Digital markets the Raptor X as the first ever hard drive designed for gamers/modders, but under its clear window this is WD's top-of-the-line enterprise level drive.