Western Digital Scorpio WD2500BEVS

The firm first wet its feet with the Scorpio WD800VE, an offering that competed against other players established at the 80-100 GB/platter mark. Shortly after, WD followed with a 120 GB unit and eventually the 160 GB WD1600BEVS, the manufacturer's first drive to incorporate perpendicular magnetic recording (PMR) techniques. While the 160-gig drive matched the capacity offered by competing drives such as the Hitachi Travelstar 5K160 and Seagate Momentus 5400.3, WD's offering more often than not trailed others in StorageReview's key performance tests.

Now WD steps up to the plate once again with its fourth-generation Scorpio WD2500BEVS. The company claims that this latest Scorpio is the first 250 GB 2.5" drive to ship in volume. The drive features second-generation PMR techniques to pack 125 gigabytes across each of its two platters to achieve its impressive capacity. WD specs the drive with a 12 millisecond seek time and equips it with an 8-megabyte buffer.

The WD2500BEVS debuts the manufacturer's "IntelliSeek" technology, a just-in-time style approach that aims to minimize power draw. As we all know, today's hard drives feature rotating platters upon which hundreds of millions of individual sectors rest. In typical non-streaming use, data from a relatively small gathering of sectors is retrieved/written before the actuator then moves to the next group. Previous drives would maximize acceleration and deceleration of the actuator to get the read/write heads in place as quickly as possible.

Under the IntelliSeek paradigm, the drive moves the actuator just fast enough to get to the appropriate track as the target sector(s) approach the heads' location. This minimizes power draw with no hit to performance since the drive would have to wait until the appropriate data location rotated under the heads regardless of when the heads arrived in position. An analogy: Consider an 11am hotel checkout and 1pm flight check-in. A traveler must leave the hotel by eleven and arrive by one, but can minimize the gasoline used by driving slowly… whether he gets to the gate by 11:30 or 12:59, he still boards the same flight and gets to his end destination at the same time.

Though it features a 5400 RPM spindle, the WD2500BEVS in effect represents Western Digital's capacity and performance offering since the firm does not currently market a 7200 RPM line. As a result, in addition to contrasting the latest Scorpio with previous-generation 160GB units, we will also include 7200 RPM drives in the mix: