I have an HP 6300 which has dual channel memory, 2 slots on one (black and white) and 2 slots on the other (black and white). I have two matching sticks of 2GB and two matching sticks of 4GB. Right now I have 2x2GB in one channel and 2x4GB in the other channel, and it is working. But is this best? Would it be better to one 4GB and one 2GB on each channel?