Hi i just got my HD 5700 in the mail. I had to go used to save a little money (hope it was a good buy). Anyway with it not being new i was wondering if i need any cords that would have came with it? Also what is this giant back plate that extends the length of the card like 6 inches?
For a 5770 all you should need in terms of cables is a 6 pin auxiliary connector, (which will be part of your PSU) a cable to connect it to your display, and a crossfire bridge if you want to run it alongside another card in crossfire. The only connection to the motherboard will be via the PCIe slot.
Don't know what you mean by a back plate though, sorry.
Ah, that's because that was a card from a Mac Pro upgrade kit then. I'm not sure why they have those back plates since I've never seen the inside of a Mac, but it's just there. As long as it fits in your case I see no reason why it shouldn't work though.
Scratch that. It seems that Mac video cards have a different ROM that makes them incompatible with PC's. (I'm assuming you have a PC here; correct me if I'm wrong.)
Youtube is hardly the most reliable source, but it's entirely possible that it's true.
Some people have indicated that Mac cards (the newer ones, mind you) are compatible with PC's, just not vice-versa, because standard PC cards are missing firmware that the Mac needs to boot but everything Windows needs to boot is present on a Mac card. (See the "What is flashing" section in this post.)
If you already have the card, it's worth a shot. However, like jsc said, unless you got it for a lot less than the price listed on that site you gave, you can get a brand new 5770 for a lot less.