Just as a note, I have that motherboard, it's form-factor is listed as ATX but it's actually not as wide as a standard ATX board so you can't go off what your case says, the easiest method of making sure you're putting all the standoffs in the right places is to put the motherboard on a piece of paper and, with a pencil, mark each of the screw holes and then use that to put the standoffs in the right places