Originally Posted by Stinkbag
I understand what you guys mean but i don't know if losing speed for quantity is better or not.
Well do you even know the speeds between the sticks at the moment? In the situation that your 1GB sticks are faster than the 2GB sticks you'd lose, you gain from adding the 1GB. If the 1GBs is the same [clock] speed as the 2GBs, then you gain here (in RAM capacity, not RAM speed).
Only if the 1GB are slower than the 2GB then do you have to worry about the downclocking, but this goes back to the difference of settings for different sticks. Your 2GBs might be 800 Mhz @1.8v where as your 1GB sticks are 667 at @1.7v. Can kick your voltage up to 1.8v and maybe get all sticks stable at 800Mhz? This is why you are here on Overclock.net, we overclock and we fiddle with settings most users won't. You can make it work if it isn't ideal out of the box and I would to get 6GB of RAM running.