I have an early 2008 Mac Pro with 4 x 1 GB memory modules. I want to upgrade and get more RAM but the whole situation of upgrading RAM in the Mac Pro confused me. I recall reading about how it was best to buy certain configurations and that the size of the modules matters (i.e. 4 x 1 GB's would not deliver the same performance as 2 x 2 GB's). But I read all of that a few years ago and now cannot seem to find the article(s) describing it. Does anyone recall this and/or provide a very easy to understand summary of what the best thing I can do with my given situation is? I've never installed new RAM or done anything inside my computer, so as simple to understand of explanation would be greatly appreciated.