In theory, disabling AAM should result in increased seek noise on the Barracuda ATA IV. Through subjective listening, however, we detect no increase in noise. Without AAM, the 'Cuda remains the quietest 7200 RPM drive that SR's ever tested in both idle and seek situations. The WD1000BB-SE's noise is, not unexpectedly, in line with the BB's. Unlike the 'Cuda, it doesn't plumb the absolute depths of today's noise floors. Even so, the drive's overall profile is hardly objectionable when used in our testbed. Remember, this test system's standard cooling incorporates only the CPU fan on the retail 700 MHz Pentium III and a PC Power & Cooling Silencer 235 ATX power supply. It's hardly a system overrun with the latest in exotic and noisy cooling.
Seagate Barracuda ATA IV AAM Conclusion: In the end, disabling AAM results in small performance increases across the breadth of our tests. Despite the improved speed, there's no detectable increase in noise. As a result, performance-minded users may wish to disable AAM to ensure that their 'Cuda delivers its absolute maximum in speed. On the other hand, however, measured increases are indeed small, so those less inclined to fiddle with their drive's settings are hardly missing out on a landmark speed increase.
In the end, does a 0.9 millisecond reduction in access time deliver? It's difficult to say. Results suggest that the difference is minimal. And remember, 0.9 ms is 75% of the reduction in access time achieved by moving from a 7200 RPM to a 10,000 RPM spindle speed. At any rate, these minimal margins shed light on why manufacturers such as Seagate and Maxtor ship disks with AAM enabled. Though the 'Cuda IV doesn't exhibit a difference in noise either way, other drives may noticeably benefit from AAM.
Western Digital Caviar WD1000BB-SE Conclusion: The BB-SE delivers mind-blowing performance increases over what already was a best-of-class drive. It not only achieves 20+% increases in metrics most relevant to single-user machines but it also yields improvements in file server performance, making it a viable option for those building a server on the cheap. Further, experimental IOMeter indices indicate that the WD1000BB-SE tops the IBM Deskstar 60GXP in a benchmark that many readers highly regard.
An increase in buffer size, properly coupled with a well-conceived caching strategy, yields dramatic improvements in performance. Though Western Digital primarily manufactured the BB-SE for an OEM order, it's clear that they're gauging the market for ultra-high-end ATA disks by offering surplus units to end-users. A survey SR recently conducted comes to mind: