Much has already been written on the topic. As typical memory specs approach 3 and 4Gb the discussion will only increase. I think it would be productive to encourage forum users who are new to the issue to scan some reference works and then move on. A short (60 words) canned answer here followed by some links would be good.
__________________________________________________ I was previously employed by Lenovo but have no formal role on this forum. I am here on my own time because I like fooling with PCs, especially Lenovo ones. ALL my posts are purely my personal opinion.