I have an asus mobo ASUS A8N-SLI,Nforce4 Ultra with 2 GEIL VALUE ram 512 memory banks in it (2,5). I want to add two more 1GB memory banks in it while still working dual channel.
Can I add just two other memory banks as long as the 2 new ones are identical or shoudl they be same size and speed as old ones?
I was told that I can add 2 1GB banks as long as they were the same speed as the 2 original ones and both new ones were exactly same.
More about :adding memory banks dual channel system
Yes, you can add another pair of RAM modules. It will work in dual channel.
Just have the 2 512MB modules paired in dual channel mode, and the 2 1GB paired on the other channel. (watch for the color of the RAM sockets).
If they are all the same speed (say 400MHz DDR), they'll all work at that speed. Otherwise, they'll work at the speed of the slowest module. (set it to AUTO in BIOS, or manualy set the speed to match the slowest module).
Also, when 4 DDR modules are used you might want to set the Command Rate to 2T instead of 1T if it doesn't work with the latter. (this is also done in BIOS settings).