Currently, I have a 2GB DDR2 RAM from Apacer running at 800Mhz on my Intel DG41RQ. Since my MOBO doesn't support DDR3, I can't upgrade to that. I'm thinking of getting another 2 GB of DDR2 RAM 800Mhz. Now I heard somewhere that, to get maximum performance, I need both of the RAMs to have the same serial number. How do I found the serial, and is it ok if it's pretty close to it?