RAM latencies
Posted: Sun Dec 19, 2004 12:22 am
looking to get more ram and i think my latency is 2.5-3-3-8 how important is it to get the exact same numbers
if you are overclocking and/or running dual channel, it is gonna be better if the ram runs at the same latencies. if you do want to run 2 modules for this purpose, matching pairs or twin modules are the best.
most boards nowadays, you can change the latencies, but if you don't know what a ram module can run, it is like rolling the dice. the important thing to look for is at what speed those latencies run. if you are buying higher end ram for overclocking, they will (or should) advertise what the module has been tested to run at and at what speed.
I have PC4000 that runs at 2-4-4-7 by SPD until i change the FSB to 232, then it changes to 2-5-5-9. When i change FSB to 250 (haven't got there yet ) it will change to 2.5-5-5-9 . It has been tested to run at 250, which is why it can be called a PC4000. Those timings are programmed into the module as SPD.
I could go in bios anytime and change those, but it for me is rolling the dice. I only change timings if i am overclocking and can't get it to run high FSB, and i suspect the ram to be the culprit.
You can look at the timings thru cpu-z 1.24, it will show you what the SPD timings are, and what it is running right now.
all that said, if you are not overclocking, you should still try to get as close as you can to the same. most ram modules will still advertise the CAS latency, if yours has 2.5, then you should try and match at least that with the same speed module (pc2700,pc3200,etc.) if you have a good board, it will usually be able to handle slight differences without a big hit in performance.
