Western Digital ships 4TB WD Black hard drive, melds speed with space for $339
 

The 4TB hard drives that we've seen gradually filter into the marketplace have come with a few snags for desktop users; they're usually either external drives we'd never boot from or pokey internal models not meant for anything speed-intensive. Western Digital doesn't want us settling. It's shipping a 4TB version of its WD Black desktop drive that holds nothing back for the sake of the extra storage, spinning at a healthy 7,200RPM while packing 64MB of cache, dual processing and a two-stage actuator that together keep the drive working at full burn. At $339, the SATA 6Gbps drive undoubtedly carries a premium in trying to be the best of all worlds; it may be worth the expense for performance-minded types who've been out of options (and capacity) for awhile.

http://www.engadget.com/2012/11/20/w...ck-hard-drive/