On Mar 15, 2006, at 1:27 AM, Snow White wrote: > Aaron: > > Do yourself a favour and do not mix your RAM. READ your manual or > check for it at Apple and get the RAM that is recommended by Apple > as the correct module. IMO The DDR will not function in that > computer and could actually break it. Actually, the MDD models have to have DDR memory. > Each of these RAM chips you named has different bus speeds and > different latency and are vastly different from one another. Since his model came with PC2100, any properly designed and manufactured PC2100 or better DDR module will work. Mixing speeds is fine. Just make sure you have return or exchange privileges from your retailer. Phil