ok, i have tried to put the GPUs in the first and the second slot but they wont fit, and at first i tried the way asus said would me best in the user maual, GPU 1 in slot 1, and GPU 2 in slot 2b, when doing this the only other slot i could put my soundcard in was the fifth slot, and when i did that crossfire dindt work. i tested my other theory where i put GPU 1 in the second slot and GPU 2 in the fifth slot, with the sound card in the forth slot, and this worked, but wil this be a optimal setup?