there are two different types of cheetah at 15000rpm

the older 15k.3 models
http://www.digit-life.com/articles2/seagate-15k3/
only up to 75 gb i think

and the latest just released next generation 15k.4 models
i think these go up to 147gb max.
http://www.storagereview.com/article...46754LW_1.html