That xfi card can indeed cause issues. I tried it in the last slot and it doesn't play well for me there. I use the xfi card that came with the P7N in another motherboard now and I'm using a cheap usb audio adaptor that works fine for what I need. BTW apologies if I seemed harsh earlier or offended anyone but there are a lot of answers to some of the most often repeated questions in this thread. I'm going to put an e8400 in this P7N later today and try some high fsb. All my quads hit a wall at anywhere from 450-470fsb. Hopefully I'll have screenshots. Have I said I like pics?