I have 4 GB (4 x 1 GB modules) of FB-DIMMs for first generation (http://"http://everymac.com/systems/apple/mac_pro/stats/mac-pro-quad-2.66-specs.html") of Mac Pro (2.0 dual, 2.66 dual, 3.0 dual or quad-core) for sale. They have the Apple-approved heat sinks and work just fine. Made by Kingston (http://"http://www.kingston.com/canada/") so they have lifetime warranty. Will include the receipt with them. Best price I can find for them in Canada is $190 + tax for both pairs. Want $120 OBO.