about to upgrade from 256ddr pc3200, and throwing in a 512dr same deal, in dual channel. will the 256 clock/slow it down for any reason? or is memory size irrelevant as long as they’re both at 3200, 2700, etc. 
As long as it can run at the same speed as the original stick, it’ll be fine. The thing that might throw a wrench in the dual-channel business is not having both sticks being the same size. I’m getting that you have 256MB right now and want to add a 512MB stick of DDR to it and put it in the second channel. If I remember correctly, this doesn’t fly.
Lastly, dual-channel will only work if your motherboard supports it.
no… or maybe yes?
i currently have 256DDR PC3200 and i want to throw in 512DDR PC 3200, and have them run in dual channel… mobo supports.
Yeah, from the way I understand it, that’s not going to fly. For best results you should get the same stick you have currently, as the Intel chipsets are a bit more stringent than others when it comes to dual-channel.
You can still add the 512MB stick, but it won’t work in dual channel.
i see, in that case i guess i’ll buy 2X256, bit more expensive but.. meh any donations?
now that 256 by itself shouldn’t cause any problems correct?
As long as your mobo supports dual channel, and your 2 sticks are identical then it should work.