Hi, I have a iMac Late 2009 which has 4GB RAM and takes 1066MHz DDR3 SDRAM. Your Mac contains 4 memory slots, each of which accepts a 1067 MHz DDR3 memory module. 2 memory slots in use, 2 available. I would like to upgrade the ram another 8gb and ideally get the same Manufacturer. How can i find out without opening the iMac to see what RAM i currently have installed. Thanks.