Ssd hybrid

For a desktop pc which is better: a seagate momentus xt hybrid (7200rpm/3gb/s) or a regular mechanical  7200rpm hard drive (6gb/s)

You would be better off with a desktop drive and if you want the caching ability a cache drive such as the one made by sandisk that comes with its own software to cache and can be used on intel or amd platform.

1tb 3.5in desktop drive

32gb ssd cache