certainly can be downclock itself during boot up~~~aj2003 said:my brother has a board that only support upto pc2100 (ddr266 i think it is) anyhow can i put a stick of ddr400 in there and will that underclock itself to the lower speed, i want to get the higher stuff cos hes gettin a new computer in about 2 months and that has 512ddr400 in it already so want to be to use this stuff in new one. thanks.