memory timings???

[munkeyboy123]

ok right now i have 4 gigs of kingston hyper x ddr2 900 running at 5-5-5-15 if im correct, but i want to get more ram for my computer, which btw is running vista ultimate 64-bit, and my mobo is an evga 680i which supports a max of 8 gigs, which is how much ram im going to buy, but ive always seen 5-5-5-15, and 4-4-4-12 timings, now i know that the lower timings equals a lower cas rating, atleast i think so, but now im seeing 5-5-5-15t2 and 5-5-5-18, and all i really want to know is if im steeping up to that much ram do i need a certain timing and voltage or anything will just about work fine? any input is grateful.

[Blitzkreig75]

You might have to 'loosen' the rated timings when running 4 sticks of DDR2. For example, I run Corsair XMS Pro, rated at 4, 4, 4, 12 @ 400MHz. But the RAM will not run that way with 4 sticks installed in my 650i mobo. Corsair's tech support and site info states that they are rated to run at advertized timings with two sticks installed. They list different, higher (looser) timings when using 4 sticks. 5, 5, 5, 18 @ 400MHz 4x 1Gb DDR2-800 T2.

I read some test info that was ran when DDR2 first hit the scene a while back and they showed that unlike DDR1, where lower timings were the 'good thing', frequencies are the 'good thing' with DDR2. So, 400MHz @ 5, 5, 5, 18 will be so close to the same performance as 4, 4, 4, 12 @ 400MHz that you likely will never feel or see the difference between the two, (there are exceptions of course, depends on your demands and apps). Make sense?

If at all possible, try to get the same branded RAM, (or at least the same timings and voltages), for these reasons, IMO, and look up the specs on the manufactuers' site. Might save you some headaches.