Hitachi's Deskstar 7K400 is the new king of big: the 7200rpm Serial ATA hard drive comes with an 8MB buffer and a staggering 400GB of storage. The drive also features improved digital-media handling capabilities and in our tests performed exceptionally well on standard desktop applications, too.

To reach 400GB in the new model, Hitachi essentially slipped two more 80GB platters into its 250GB Deskstar 7K250 - the fastest hard drive we have tested to date. Adding the extra platters didn't affect performance: the 7K400 completed our tests in 34 min, 1 sec - 21 sec slower than the 7K250, a statistical tie. And in both our Windows and our applications-based tests, it outperformed the average score of all seven 200GB or larger hard drives we've seen, often by 9 to 16 per cent.

The drive is not only speedy; Hitachi says it also excels at streaming video - a key function of PCs used as digital video recorders - thanks to its new Streaming Command Set. And at $400, it's a fairly economical way to prepare a new or existing media-savvy PC for high-definition content, where each hour of video can require 8GB or more.