Remarkably, decreased noise levels accompany the X15-36LP's new level of performance. Idle noises, both in terms of high-pitched whine and lower "hums," are quite unobtrusive when masked by our relatively quiet power supply and drive cooler. Just last week we were amazed at the Maxtor Atlas 10k III's low levels of idle noise... the X15-36LP approaches the noise floor offered by the Maxtor! Seek noise, while not as muted as the typical ATA drive, is nonetheless impressive. The sound is more reminiscent of a good 7200 RPM SCSI drive's seeks rather than the rumble the early 10k RPM drives exhibited.
The X15-36LP runs just short of being too hot to touch after running through our IOMeter suite (2 hours and 37 minutes of intensive accesses) in a drive cooler. This means that despite its lower platter count, the drive runs hotter than its predecessor. Though our testbed case is small and our cooler and power supply fans are quiet (and thus don't move much air), we nonetheless recommend careful installation to ensure that the drive runs within its operating temperature limits.
In conclusion, the X15-36LP delivers mightily on all fronts: the lowest access times, the highest transfer rates, the highest WinBench 99 scores, and the highest IOMeter scores that we've yet recorded. That it does so with lowered noise floors is all the more impressive. There are only two drawbacks involved. The first regards heat. Though its not nearly as hot as the scalding IBM Ultrastar 36Z15, the X15-36LP does seem to run hotter than its predecessor, somewhat disappointing considering its reduced platter count. Price is the other factor... the drive runs upwards of 40% more than a 10k RPM drive featuring the same capacity. These two quibbles, however, are minor indeed in the eyes of targeted users. Make no mistake about it, the Cheetah X15-36LP is the fastest hard drive one can buy for any and all applications. Period.