I just bought a 1GB stick of Kingston 667MHz, PC2-5300 DDR2 RAM. My MBP came with one Samsung RAM. I have made sure that the speed and size of both the RAM's match, but i was wondering if it really makes a "matched pair"? Is there a piece of software or a script which can determine if the RAM pair is matched or not? I tried running the following command in terminal, but it returned nothing: ioreg -p IODeviceTree -n memory -S | grep ram- Thanks in advance.