Western Digital Raptor WD360GD
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Western Digital is in many ways the perfect company to lead ATA to a next-generation spindle speed. Ever since it introduced the Caviar WD400BB, WD has consistently led the field in ATA performance. That is a 2.5-year run at the top- very impressive in the competitive computer hardware field. More importantly, however, the firm has no SCSI business to protect. The last thing that established SCSI powerhouses such as Seagate, IBM, and Maxtor want to see is the erosion of the relatively cushy margins associated with SCSI drives. Now that WD has opened this veritable Pandora's Box, the competition is sure to follow.
According to WD, the key factor holding back higher spindle speeds was parallel ATA's lack of specification-level hot swap functionality. To be successful (initially, at least), any 10k RPM ATA drive must gun for the enterprise market. And in the enterprise, a sector that views minimal downtime as critical, the ability to seamlessly swap out a failed drive another is crucial. Serial ATA provides for such hot-swap functionality. Now that SATA is trickling into the channel, WD believes 10k RPM ATA's time has arrived.
The Raptor comes in just a single configuration- a single 36-gigabyte platter. WD specifies the drive's seek time at just 5.2 milliseconds, solidly within SCSI territory. An 8-megabyte buffer accompanies the unit. Some folks may be disappointed with the disk's relatively paltry capacity- after all, today's SCSI drives deliver 147 GB of storage in a low-profile chassis. Much like its namesake made popular by 1993's Jurassic Park, however, WD envisions Raptors in multiple-drive configurations running off of relatively inexpensive SATA RAID controllers. Reflecting its enterprise orientation, the Raptor claims a 1.2 million hour MTBF spec and features a five-year warranty.
It is important to note that the market for the Raptor is primarily the entry- and mid-level server segments and not the enthusiast desktop sector. When Western Digital raised the bar nearly 1.5 years ago, we repeatedly pointed out that the Special Edition (JB series) Caviar was what readers really wanted when they speculated over 10,000 RPM ATA drives. Equipped with an 8-megabyte buffer and accompanying firmware aggressively tuned for single-user scenarios, the WD1000JB easily matched and even exceeded the performance that the best 10k RPM SCSI drives of the era delivered when it came to desktop performance. While SCSI disks feature superior mechanics, their server orientation forces them to trade away firmware optimized for highly-localized patterns in favor of strategies that maximize returns in random access scenarios. In the Raptor, WD faces much of the same quandary. With its enterprise-class warranty and seek time, however, the firm attempts to target server markets.
Initial tests run on a pre-production sample supplied by long-time sponsor HyperMicro yielded disappointing results. Immediately afterwards, however, Western Digital was eager to get a production-class unit in our hands. Retrospectively, there were three key factors that prevented the beta sample from achieving maximum performance. First was the lack of write caching, especially apparent by the model's poor showing in the SR High-End DriveMark 2002, a pattern that emphasizes write performance. Secondly, the pre-production drive utilized platters that were not optimally low-level formatted. Lastly, the drive suffered from an older firmware revision.
The production sample, of course, addresses these concerns. Our initial beta sample figures were drawn in conjunction with a Promise SATA TX4 controller. Though we also ran tests with a Silicon Image 3112A chipset, the combination resulted in exceptionally poor results likely arising through some unpredictable interactions between the drive's firmware and the SI chipset. The production unit, fortunately, does not exhibit the same problems. Though Promise's controller delivers superior results with the Raptor, we have presented results with SI's chipset due to its prevalence in the controller market.
How does the Raptor perform? Let us turn to some numbers!