We were expecting Seagate Barracuda XT 2 TB to smash its main competitor, Western Digital Caviar Black 2 TB, because of the use of the new SATA-600 interface, but this didn’t happen: both achieved the same performance level. In fact, Western Digital Caviar Black 2 TB achieved a somewhat lower access time; so if you are looking for a fast 2 TB hard drive, Western Digital Caviar Black 2 TB has a little bit of an advantage.
It is very important to have in mind that when a new interface is released this kind of result is not unusual, especially with the very first product. As we have explained in the introduction, the new interface expands the maximum transfer rate the interface can handle, but that doesn’t mean that the hard disk drive itself is faster. It should take a while for us to see drives that can benefit from this new interface. In fact probably SSDs will have greater benefit, as many of them are reaching more than 200 MB/s today, so they may reach the 300 MB/s limit way sooner than hard disk drives.