CL (in Ram) comparison

[Seeker47]

Crucial's site says lower is faster . . . but of course there are other relevant factors.
My question: in comparable Ram options that you could install, would a CL rating of 4
really make that much of a difference, vs. a CL of 5 or 6 ?

[poisondeathray]

not much difference

running at the same bandwith, a lower cas latency is faster

the difference varies by application, but the difference is about 0-2% overall between cas4 vs cas5. If you visit some of the tech sites like anandtech, xbit, xtremesystems forums a few others, numerous comparison studies have been done

some applications run faster with higher bandwidth, some lower latency it depends on the bottleneck; again it's application specific. Usually when you do your memory settings, there is a trade-off between bandwith and latency (i.e. either high bandwidth or tighter latency settings). Most applications in Windows are not memory bandwidth starved, so using a lower latency is usually the better choice. This includes most games, video apps, general office programs.

also some motherboards may limit the memory settings that you are able to run at, to unlock the best performance, you need a good bios and a good mobo

[Seeker47]

not much difference

Thanks for the info. I have two sets of Ram that I could plug in, both from Crucial (their basic line, not the Ballistix or the one with the heat spreaders and LEDs), both bought at a good sale price. One is a 2Gb. kit, 5300 / 667, with the lower CL figure. The other is a 4Gb. kit, 6400 / 800, with the higher CL figure. Either would meet the MB specs, as is. (Whatever overclocking may be possible, I'm not really interested in doing that.) I'm leaning towards going with the 4Gb kit, even though Windows may only recognize 3.5 of that. I've seen differing reports about that regarding XP, which is what will be running on the box in question.

[redwudz]

A 32 bit OS will use about 3.7GB or thereabouts. Some may be used by the video card. If your motherboard can run 6400/800, that would probably be the better choice. Faster RAM usually has a higher CL, but should preform better.