if you're wondering about dual channel memory, the motherboard has to support it. if you're not sure if yours does, check the manufacturer's website for your model and it should tell you, since it's a pretty important feature. and i think you typed before u thought. for 1GB of Dual Channel DDR, it'd be 512x2, or 256x4. about brands of memory or motherboard, any motherboard that supports dual channel would be fine, as long as it meets your other needs too. don't think there is a difference between one companies dual channel DDR and another's. also don't know about RAM brand. if you want fast memory, there's always i think it's Crucial Ballistix or something, which uses good timings, but also costs a bit more than your average DDR. It's all a matter of preference going by brands really. me, i usually go with whatever i can at the time.
