Seagate still trails behind WD, because its 1 TB Barracuda 7200.11 isn't available yet.
The storage marketplace has grown noticeably faster than have markets for other PC components in the past few years, primarily because hard disks are being used in more and more devices. These have a way of showing up in living and family rooms, unlike PCs: consider high definition DVRs, for example. Nevertheless, the subject of hard disks is often described as odious or boring, because big capacity targets have already been attained, and not much new has come along in many months. After drives hit the 250 GB mark, there was a long pause in new developments. Then, if Hitachi hadn't come through with a 5-platter 500 GB monster, WD would have trumped the field with its 400 GB Caviar drive. Next, Seagate led the pack with its 750 GB Barracuda, after which the hard drive market languished for nine months before the Hitachi 7K1000 Terabyte Deskstar came along. Now, after a year off from running out front, Western Digital once again takes a lead, and blackens a few competitors' eyes in the process. In short, it looks like there's major movement in the hard disk market once again!
After numerous improvements to the underlying technologies involved, it looks like Perpendicular Magnetic Recording (PMR) is responsible for most of the latest performance and capacity gains. Magnetization is no longer horizontal, following the lines of rotation around the disk platter (also known as longitudinal recording). Now, it's vertical and extends into the surface of the disk platter itself. This enables much greater data densities in the same surface area, and as a happy consequence, also speeds up the rates at which data may be read or written. Other hard disk performance parameters, such as drive cache size, play only an ancillary role, as we explain in our article Understanding Hard Drive Performance.
Seagate was the first company to release products built around PMR technologies. Other vendors, including Western Digital, tend to be a bit more conservative when it comes to adopting new technologies. Their latest product, though, the Caviar SE 16 WD7500AAKS, need not surrender pride of place to any of the competing Serial ATA drives currently available. This latest 750 GB top-of-the-line offering beats all the other 7,200 RPM drives, and performs on a par with the 10,000 RPM WD1500 Raptor (although it cannot beat the 74 GB version, the WD740).
We did our best to dig into just how the new Caviar SE16 WD7500 performs Compare Prices on Caviar 750 GB Drives.