It's official: Hitachi has joined the 3TB party. Fittingly, the hard drive maker has a trio of products with 3TB storage capacities. The first and perhaps most interesting is the Deskstar 7K3000, which spins its 3TB at a speedy 7,200-RPM. Hitachi doesn't reveal how many platters this drive uses, but the spec sheet (PDF) mentions an areal density of 411 Gb/in², which suggests a five-platter design. That wouldn't be unusual for Hitachi, which stacked five platters with its first 1TB and 2TB models. Western Digital's Caviar Green 3TB is a four-platter design, although its platters spin at a mere 5,400 RPM.
Hitachi quotes an impressive maximum media transfer rate of 207MB/s for the 7K3000. The very same spec sheet fails to mention the drive's access time, although it does reveal a 64MB cache and a 6Gbps Serial ATA interface. Those last two elements are pretty standard for modern 7,200-RPM mechanical drives.
As one might expect, all the usual caveats about running 3TB drives at full capacity apply to the 7K3000. Hitachi has put up its own page detailing the compatibility picture, which looks to be the same as for the Caviar Green. The Green comes with an auxiliary SATA card that lets you boot from the drive on systems that lack an EFI BIOS, but you're on your own with the Deskstar, whose $250 suggested retail price is only $20 more than the slower WD drive.
While the 7K3000 has been shipping since November, the press release also mentions that a 3TB Deskstar 5K3000 is due to head out the door next quarter. Hitachi doesn't get into specifics on this low-power drive's spindle speed, listing it only as "CoolSpin" on the spec sheet (PDF). Something in the neighborhood of 5,400 RPM seems like a safe bet. The 5K3000's maximum media transfer rate is pegged at 171MB/s, which is still pretty quick, but you only get 32MB of cache and a 3Gbps SATA interface.
I suspect the 5K3000 is arriving late because the first batch has taken up residence in Hitachi's third 3TB product, the XL external drive. The 3TB version of this drive carries a $250 MSRP, and I really doubt Hitachi is throwing in a 7K3000 and giving you the USB interface and enclosure for free. Not that the speed of the drive matters; inexplicably, the XL is saddled with a lowly USB 2.0 interface that's going to cap real-world transfer rates at around 38MB/s. Waiting for three terabytes of data to trickle onto the drive at that speed sounds like all kinds of fun.