Alright, I am posting for a friend. He currently has a X2 3800+ with 1GB of RAM (in 2 512MB sticks). He is looking to upgrade to 2GB. However, I don't know what would be better. Getting 2 more 512MB or a 1GB stick? I hesitate on the 1GB stick because I'm not sure if it would take his system out of dual channel mode.