livingfortoday said:
Because they're pricey, and they just finally came out with a 150GB SATA version of one. It's $274. So... yeah. You can get a lot more storage for that price, and 7200rpm is enough for most people.
Not only that, they are HOT.
And there's a misconception about performance: It isn't about RPM, it's about track density. THe performance you get from a 10,000 RPM drive is not 10/7 times the performance of a 7200 RPM.
In order to build a 10,000 RPM drive Western Digital made the diameter of the platters smaller - under 3" as opposed to about 3.25".
What happens is that during a given revolution of the platter, on the outside tracks more bits are passing under the heads on the larger platter than the smaller one, because the track is longer (perimeter) yet passes under the heads in the same length of time. This is why if you partition a drive the first partition of a hard drive (on the outside tracks) performs better than partitions on the inside tracks of the drive -- the inside ones have to take more spins of the platter to get the same data read.
So the Raptor spins at 10,000, but gives away some of its performance by having a smaller platter and starting at what would be 1/4 the way inside a full size drive. That's also why a 7200 RPM 2.5" laptop drive will never equal the performance of a 7200 RPM 3.5" desktop drive.
Two other ways to improve performance without changing the RPM is to increase the areal density of the platter (which is what Seagate and others are doing with perpendicular recording, which packs the bits closer) and by having more platters and more heads on the same drive, and interleaving the data between the heads.
For these reasons, you'll see the new, large (500 Gb) perpendicular recording 7200 RPM drives outperforming the 10,000 RPM Raptors soon.
