Seagate's venerable Cheetah series now features five-generations of tried-and-true 10,000 RPM spindle speed technology. The Cheetah 4LP broke new ground as the first drive to feature 10k RPM speeds as well as a sub 8 ms seek time. Its successor, the Cheetah 9LP, elevated things to a new level by shaving seek time down to just 5.2 milliseconds. Since then, however, Seagate's 10k improvements have been evolutionary at best. Though the 18LP and the 36LP took advantage of ever-increasing areal densities to deliver higher capacities and transfer rates, access times remained constant. Seagate's next-generation unit, however, finally features a reduced seek time. Do we speak of the 36XL?
Well, no, not quite . With its "XL" designation, the Cheetah 36XL is more of a "half-generation" update. The 36LP, after all, already delivered a Seagate low-profile 36 gig 10k unit. So what does the 4.5th generation 36XL offer? Improved areal densities and a resulting platter count decrease, of course. The 36XL requires just 4 platters do deliver its 36 gigs of capacity. Buffer size, at 4 megs, remains unchanged. Spindle speed, of course, is 10k.
Seek time diverges a bit from predecessors... upwards, amazingly. While the Cheetahs 9LP, 18LP, and 36LP all featured a 5.2 millisecond rating, the 36XL comes in a hair above, specified at 5.4 ms. Why? Perhaps the increased areal density... the 36XL packs 50% more data per platter than the 36LP. We'd figure that decreased platter count, however, would offset the extra precision that higher densities require. As we'll demonstrate, all this hair-splitting is unnecessary- specified seek times aren't always reliable.
Seagate positions the Cheetah 36XL squarely at the mainstream SCSI workstation and server markets. Unlike the higher-end 73LP, the 36XL is available only with the Ultra160 SCSI interface... there aren't any FC-AL versions. An industry-standard 5-year warranty backs these enterprise-class drives.
Let's see how the 36XL's low-level measurements stack up.
WB99/Win2k Low-Level Measurements