crazy359 :
YOU DO NOOOOOOT NEED TO BUY ANOTHER ONE!
DDR3 means u run in sticks of 3..........so 3.......6........9........12 and so on.
So if you have 4gb or 8gb that puts it into DDR2 MODE.
Don't know you came up with that put I'll give it an A for blind creativity.
DDR3 means the 3rd revision standard for Double Density Ram. Has nothing to do with the MODE or quantity being used.
fonkydog,
You can run with just 3 slots filled even on your dual channel mobo. Might not run in dual channel (similar to a RAID HD setup,) but it will still run and probably won't be any significant hit to performance. Are these 2gb or 1gb sticks you have already? Depending on what you use your PC for, just using 2 for 4 gigs will be more than enough for gaming and you can sell the extra stick. If you have 1 gb sticks, JDFan has it covered, timings, voltage, size if you really want, but 3 gbs should be more than enough for gaming too. If you 're doing HEAVY production editing, then going to 8gb might be worth it if you have 3 or 4 resource hungry apps running with a large project.