Hello, I currently have an HP G62-364dx laptop and I want to upgrade the ram. Right now it has a 2gb card and a 1gb card. As far as I know this laptop supports dual channel memory. So my question is, would it be better to buy a 4gb card and get rid of the 1gb and have a total of 6gb or get rid of the 2gb and 1gb and get 2x4gb cards to use the dual channel?