Long story short, I upgraded RAM in my MBP to 8GB. I have the two old 2GB sticks in a box. Can I use them to add onto my parent's iMac? From what little I've done, it seems possibly. My only concern is that the 2GB sticks I have lying around are 1600MHz and my parent's iMac uses 1333MHz. I know standard computer hardware will down clock the faster RAM to the slower RAM's speeds. Will iMac logic boards do the same? Thanks in advance!