There's also the extra cooling pipe and larger heat sink on the north bridge chip. Also, the mosfets on the top of the board have a heatsink on them whereas the P5K-E doesn't have a heatsink on all of the mosfets. I heard that the Deluxe has mosfets on the bottom of the board as well, whereas the P5K-E does not. I bought the P5K-E myself, but I have not yet been able to install it (awaiting the rest of my parts). I know that the pcb is exactly the same since the sticker that says P5K-E on it lifts to reveal P5K Deluxe printed underneath.