I'm going to upgrade my computer, but I got a few questions about the RAM. Right now I'm running Kingston ValuRam, DDR333, 2 x 256 MB, Dual Channel, 512 MB total memory. I'm thinking of upgrading to at least 1 GB. I want to keep the memory modules I have in now, but I'm not sure what effect that will do. I was reading that to be on the safe side for compatibility, I should get the same brand, and same speed. My question is, will dual channel be "turned off" if I get the same exact modules (will now be 4 x 256 MB)? If so, how much of an impact will there be on performance? And if it will be "turned off", would it be better to go for bigger memory? If so, how should I go about it? Buying the same brand and speed, could I just buy a single stick and would it work?