I'm planning on purchasing this computer... http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1576696&Tab=0&NoMapp=0 its an eMachines T6212 But, in all of the reviews, it says u need to replace the memory in pairs. Here it waht someone said in a review (u can see other reviews on the page..) MAKE SURE you fill BOTH slots with matching pairs ie. 256 DDR - 256 DDR in slot 1 and 2 : 512 DDR - 512 DDR in slot 3 and 4. So, i wanted to put in another 512, to make 1 gig of RAM. Does that mean that i need to put in 2 256 MB sticks? Could i buy 2 seperate (but the same) 512MB sticks, to make it 1.5 Gigs of RAM? this was the ram i was going to get... http://www.tigerdirect.com/applications/searchtools/item-Details.asp?EdpNo=586829&sku=ULT30215 i wanted to get 2 sticks. Please post soon, as i am planning on placing my order sometime tonight.