More than the full drive concept, I suggest you check your running applications. I upgraded my laptop memory from 256 to 1 gig and my hard drive from 40 to 40 gig. I didn't see any noticeable improvement in speed or performance until I reloaded the new HD only with the programs I needed to use. I saved all the old, non-essential programs to the old HD and made sure only the essential programs were booting up at START. Now my speed and effeciency are top notch.