   RAM question, DDR speed related
  I've just bought some new RAM (2 one gig sticks) to put in my machine. It currently has 1 gig in it (comprised of 2 512 meg sticks). In my motherboard manual it says that if I only use two slots my ram will run at DDR400, but if I use all four slots it will run at DDR200.So my question is, is it better to have 2 gigs running at DDR 400 (and not use the old 512 meg sticks) or use all the sticks and have 3 gigs running at DDR200? The ratios seem to intuitively say that the former is better (for pure speed anyway), but I'm sure theres more to it than that ;) any thoughts?   
Quote:Original post by Vyper_ukI've just bought some new RAM (2 one gig sticks) to put in my machine. It currently has 1 gig in it (comprised of 2 512 meg sticks). In my motherboard manual it says that if I only use two slots my ram will run at DDR400, but if I use all four slots it will run at DDR200.So my question is, is it better to have 2 gigs running at DDR 400 (and not use the old 512 meg sticks) or use all the sticks and have 3 gigs running at DDR200? The ratios seem to intuitively say that the former is better (for pure speed anyway), but I'm sure theres more to it than that ;) any thoughts?you want to run 2 gigs at ddr400... no need to cut your speed in half for a little bit of extra ram that you won't be taking advantage of anyways. plus this way you get to put the, 2x 1 gig sticks i assume, inot dual channel mode, which almost doubles your bandwidth.plus, mixing new ram with old ram might not go so well since there are differences in ram ic's, like tccd, bh5, bh5 utt...etc not to mention varying ram timing and voltage needs for the different pairs.   ;  Thanks I'll give that a try then   