So yes, you would benefit from running two sticks, which would provide double the bandwidth due to the dual channel operation, over your single stick. Obviously you don't want to just go get any stick of memory. You want to get the exact same model as what you have now, to have the best chance of them playing nice together. There is always a chance though that you'll have to actually buy a two DIMM kit that comes with matched sticks. Sometimes memory that wasn't purchased together in the same kit, just doesn't want to play ball. Usually though, if it's a lower speed kit that it within JEDEC specs, it's a lot more forgiving.