I have a problem with RAM memory. I have P8P67 Deluxe motherboard and 2x4GB RAM. I put the RAM in first and third slot but don't work, lighting mem ok! button and pc restart after 10 sec, i push mem ok! button and nothing, same case with second and fourth slot, only work on third and fourth slot in single channel? PC work normal in signle channel only in third and fourth slot, before is work on second and fourth slot in dual channel, but i'm clean all pc, and after that didn't work in dual channel, as it was before work. Any idea? Sorry for bad English