True. Unfortunately, Apple discontinued its tower, and that leaves you with two out-of date systems -- the Mac Pro and the mini -- that are not designed to be u

True. Unfortunately, Apple discontinued its tower, and that leaves you with two out-of date systems -- the Mac Pro and the mini -- that are not designed to be upgradeable. This is a problem with proprietary systems like Apple, where you have no alternative hardware supplier. If Apple doesn't want to make it, you can't have it (unless you can Hackintosh it).