Crucial makes a lot of the RAM that Apple uses. They have an excellent web site that explains RAM in great detail. Their web site also is easy to use for ordering; just enter your model info. I am very happy with crucial.com OWC (Other World Computing) is also highly regarded by folks. Al Poulin Anger, hate, and revenge are for the devil, forgiveness is for God, proactive self-defense is for the rest of us. On Dec 12, 2004, at 11:54 PM, hec wrote: > hi, > > i have a mdd dual 867 and i would like increase the ram by 512 mb. i > have a few questions. are there different makes of ram, if so does > the quality and reliability vary? are there companies that group > members find to be better? > > according to the specs at the apple site this machine says that is > machine can use pc2100 or pc27oo memory (there is a single 256 mb > pc2100 in it now). what is the difference between the two types and > how do they influence how the machine works?