Even a quick glance shows that the new WD7500AAKS looks a bit different from its predecessors; its appearance gives this new top-of-the-line model a cool demeanor worthy of the Caviar cognomen. What catch the eye are a black drive enclosure and a silver-toned aluminum deck, along with back elements on the upper surface. The white label provides the necessary descriptive information.
This new drive also delivers on the promise implicit in its snazzy appearance. It's built around four drive platters of approximately 200 GB each to offer a total storage capacity of 750 GB. There are also other variants available in capacities of 500 GB (three platters), and 400, 320, and 200 GB (two platters). All of these offer the same stellar performance, though at more attractive prices. When looking for these drives, pay close attention to the make and model designations, all of which end in AAKS. We hope to lay hands on some of these other models soon, so that we can include them in our comprehensive hard disk performance charts.
The remaining vital statistics come straight from the drive label: Serial ATA/300 with Native Command Queuing (NCQ) provides the interface to the SATA controller. At data rates of 160 MB/s, the performance of this interface lags somewhat behind the rated speeds of 190 MB/s you see on other high-end hard disks. The actual transfer rates off the storage media approach 95 MB/s, though, which makes the interface transfer rate relevant only to read performance from the 16 MB drive cache. Otherwise, this number seldom registers much importance.
The average seek time of 8.9 ms results in an actual, middle-of-the-road access time of 13.3 ms - a good set of numbers, seldom exceeded on 7,200 RPM hard disks. Those looking for faster I/O performance or significantly shorter access times must turn to the 10,000 RPM Western Digital Raptor instead, with its average access time of around 8 ms.