I have a Dell Optiplex on the way from e-bay and I would like to go ahead and order some more ram so they get here about the same time but I am having a hard time finding out what ram chip to get for that model. I normally don't have a problem looking up the correct ram but I am getting suggestions for PC-2-5300 and PC-2-6400 as well as some others. I know that it uses DDR2 but the rest is confusing me. I understand the chip speed such as 667mhz or 800mhz but the rest I am unfamiliar with. Could someone please tell me what type of ram chip I need to get? I am going to get 1mb sticks so I don't care if they are exactly the same as what comes with it because it only comes with 215mb of ram so if I get one with a faster speed then it won't matter cause 215 mb is nothing for ram. Please help me with what ram chip to put in this unit if anyone can and thanks.