I worry about what this will do to power safety. Imagine you need to rewrite a few k in the early part of a band. The drive has to rewrite the whole rest of the stupid thing. Now the power fails partway through the rewrite. Whoopsy. Well, I'm sure those other bits that have been assumed safely written and not touched in months weren't that important...
"Cold" storage probably isn't the best way to describe it either. Spinning 5" platters would take a lot of power.
Look at how e.g. current Velociraptors spin their 2.5" platters at 10,000 RPM, while using significantly less power to do it than current 3.5" platters take to spin at 7200 (http://www.storagereview.com/western_digital_velociraptor_review). Heck, it even takes a bit less power than 3.5" at ~5900 (http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears).
I'd lay good odds 5" platters would still take more power than the raptor if we spun 'em at 4500. And who the heck wants that?
Actually, I believe both Seagate and Toshiba use 3x1TB platters on their 3TB drives in the current series, as well as 1x1TB on the 1TB's. They just "mysteriously" use 3x<something else> on the 2TB drives instead of 2x1TB, and keep on with the gymnastics at 4TB too.
Actually, not. As near as I can figure, only the 1tb and 3tb versions use 1TB platters. Note that the 2TB is a 3-platter design; I'd guess it and the 1.5 are using their older 750GB platters (though the datasheets still claim the 600-whatever gbit/in density)
No, it presumably means the 250GB is physically a 333GB, and the 500 a 666. 333GB per platter, and 1/2/3 platters in the various sizes.
(well, I guess it's theoretically possible they could be selling a 3-platter very short-stroked design as 250, but that would be nuts)
I'm given to understand that hard drives are also one of the harder-hit products from the Japan earthquake, in that several HD components (actuators?) are among the products whose manufacturing was heavily centered in the affected areas.