I have an Asus P4C800E deluxe. I just bought 2X1gb pc4000 DDR ram. I currently have one 256 mb and a 512 mb in separate channels(memory is old, probably pc2100). I'll be putting the new ram in one dual channel config, but what should I do with my left over ram? I'm not sure how the other 2 slots work, concerning different speeds. I know in 1 pair of channels, you want them the same. But does that carry over in the 2nd pair of channels? Basically, ditch old ram? or use the 512 mb stick and 2X1gb in another pair.