Just wondering if it makes a difference compatibility wise is the card is say DDR2 or 3 vs it being a GDDR? or will it work so long as you have the PCIE x 16 slot?
Yes, Windows has been well known for not supporting GDDR(2|3|4|5) graphics cards. If you are running 32bit Linux, you will have to install a huge driver that can be up to 40GB. If you have a Mac, they can only use graphics cards with FUCU (Fully Underclocked Cache Use).