Which slot to put graphics card in?

[Bigpurp]

Hi everyone. Rite now im trying to install my gtx 280 in my mac pro 1 but it will not fit in the first pcie slot. I know its pretty easy to get it in on the 2nd slot, but im just wondering if it will work? Or do all graphics cards have to be on the first slot? I read here that you can either put it in the first or second. So Im just making sure.

I already took the stock 7300 out of the 1st slot though.

 

[Tallest Skil]

What do you mean "will not fit"?

Leave the Mac card in the first slot or you won't be able to boot in OS X.