Why the latest edition? We're using the 2nd edition (from 1998) in my computer architecture class this semester and it seems just fine. Even better was getting it off Half.com for <$10 after shipping.
Personally, I think that the latest edition has a lot of valuable material on parallelism and GPU programming. It's not strictly necessary for what he was asking, but its good stuff to know nonetheless.
Wow, that's a good deal. In my comp arch class, we've been forced to get the newest edition -- that is, the 4th edition, revised. Different from the 4th edition, which we used in computer organization last semester. I'm not sure how much new material has been added, but there's certainly a hefty price increase associated with buying the newest edition.
