Hi ! I am trying to better understand the various MacPro Models, can you help me please? I am looking at these links: (Maybe a better spec link exists?) http://en.wikipedia.org/wiki/Mac_Pro http://guides.macrumors.com/Mac_Pro I think I'm fairly well down patted on what a MacPro 1.1 is, however just to confirm this model does not have the 64-bit EFI? It seems to me it might be difficult to tell with the various 3Ghz models for sale on ebay if or when the video card has been changed, or they don't give the full specs? The speed of the memory does increase over each model, another indicator? Does there exist perhaps and easier to read list of specs for each model in the MacPro range? How upgradeable are MacPros, you would have to change the entire motherboard / logic board from say a MacPro 1.1 to the current model? Does Apple offer these upgrade paths, as they used to with older computers back in the day? I am sorry for so many questions, I am looking at buying a second hand MacPro in the next couple of months to move away from Windows PCs and come back to MacWorld. Maybe a lot of this is already answered elsewhere, if someone can point me to a link or something to go and read that would be appreciated, thanks.