Originally Posted by
Anubi
If only running with 2 sticks the black slots are better from a technical stand point. With DDR3 the signal termination for the DDR channel is on the DIMM, if the DIMM is in the first slot, the signal travels from the MCH, down the DDR channel, part goes up the first slot and terminates in the DIMM. But part continues down the DDR channel to the second slot and because it's empty it doesn't have any termination. This causes it to reflect, effectively the signal bounces off the end of the pins in the empty slot and the reflecting signal can mess up the good signal at the first DIMM.