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What does better CAS Latency actually give you?

So.. pretty self explanatory

Anyone mind linking, explaining, etc?

Cause I find it hard to believe a CAS Latency of 7 vs 9 makes a big difference in much

If this is true, people might as well save money and buy CL9 RAM?
11 answers Last reply Best Answer
More about what latency give
  1. Best answer
    It makes a tiny difference.

    I don't have the link handy, but there's a comparative benchmark on another site showing the differences between RAM at different speeds (1333 v 1600 v 1866, at least) and different latencies (9 v 8 v 7). The conclusion was the 1333 -> 1600 was a worthwhile change, but faster than 1600 made little difference, and that latencies made even less difference.

    So yes, 1600 CL 9 is good enough for most of us. If you are utterly obsessive, and you've already squeezed the last little bit out of the rest of your system (huge heatsink, massive overclock, etc) then maybe you could squeeze a tiny bit more out of your RAM. Probably get more out of clocking the RAM faster than by changing latency, though. In fact, you might have to relax the latency to get a higher clock.

    To be honest, I bought CL 8 over CL 9 partly because I expected it to be higher-tested RAM, and partly because the colour of the heatsinks on the RAM matched the heatsinks on the motherboard :D The difference in price was less than 10% (less than 1% of the system price) - otherwise I'd have taken the sensible choice and gone with the CL 9.
  2. I got CL7 RAM myself, I heard its better for gaming, but if the same frequency with a CL of 9 is like $12 cheaper, for like lower end/budget builders thats kind of worth it since they try to cut corners everywhere
  3. compulsivebuilder said:
    It makes a tiny difference.

    I don't have the link handy, but there's a comparative benchmark on another site showing the differences between RAM at different speeds (1333 v 1600 v 1866, at least) and different latencies (9 v 8 v 7). The conclusion was the 1333 -> 1600 was a worthwhile change, but faster than 1600 made little difference, and that latencies made even less difference.

    So yes, 1600 CL 9 is good enough for most of us. If you are utterly obsessive, and you've already squeezed the last little bit out of the rest of your system (huge heatsink, massive overclock, etc) then maybe you could squeeze a tiny bit more out of your RAM. Probably get more out of clocking the RAM faster than by changing latency, though. In fact, you might have to relax the latency to get a higher clock.

    To be honest, I bought CL 8 over CL 9 partly because I expected it to be higher-tested RAM, and partly because the colour of the heatsinks on the RAM matched the heatsinks on the motherboard :D The difference in price was less than 10% (less than 1% of the system price) - otherwise I'd have taken the sensible choice and gone with the CL 9.



    Thanks for the informative answer. I've been wondering about this if would make much difference to my "plain vanilla" computing for financial trading (lots of 2D charts mostly) and lots of net surfing. I've already ordered my 1.5 volt, 9-9-9-24, 1600 RAM for my i5 2500K and ASRock Z68 Pro3 Mobo. I don't know if I need much faster for what I do.
  4. Cant you change frequency anyway? You can OC RAM, so... but you cant OC the CAS Latency, well I guess tweak would be the term
  5. garyhope said:
    Thanks for the informative answer. I've been wondering about this if would make much difference to my "plain vanilla" computing for financial trading (lots of 2D charts mostly) and lots of net surfing. I've already ordered my 1.5 volt, 9-9-9-24, 1600 RAM for my i5 2500K and ASRock Z68 Pro3 Mobo. I don't know if I need much faster for what I do.


    You don't :)

    That RAM will work just fine for you.
  6. reaper2794 said:
    Cant you change frequency anyway? You can OC RAM, so... but you cant OC the CAS Latency, well I guess tweak would be the term


    You can try. It may work, it may not. Chances are that you won't do any harm by trying.

    You may find that, for example, 1600 9-9-9-24 can run at 1333 8-8-8-24 (don't get too upset if it doesn't).

    You may find that 1600 9-9-9-24 RAM will run at 1866 9-9-9-24, or maybe it has to be 1866 10-9-10-27, or something like that. Or maybe it will do it if you slightly over-volt the RAM (Intel strongly recommends not going over 1.65V, though, to avoid long-term damage to the CPU).

    You may find that it will run at higher specs when it's cool/cold, but won't when it's hot.

    You can waste a heap of time trying all these combinations. Or you can say "it makes very little difference to the performance of my machine, anyway", and run it at the specs on the DIMMs :)

    You'll get more performance from over-clocking the CPU than from messing around with the RAM.
  7. compulsivebuilder said:
    You don't :)

    That RAM will work just fine for you.


    Thanks again Compulsive. By the way, the ram I bought was GSkill Ripjaws. (like a million other buyers at newegg.) They were having a 15% off ram special that day.
  8. Yeah I got G.Skill Ripjaws, I guess I just might as well recommend CL9 from now on.. I have yet to understand how CL7 helps what so ever..
  9. I've seen benchmarks that show RAM with lower timings having better minimum FPS levels. The average FPS and maximum FPS stayed pretty much the same, but the minimum FPS increased. The difference was only a couple of FPS, and only in some of the games tested.
  10. So Im still getting the vibe that its not worth the extra money /:?
  11. For most people, it's not. If you are one of those people who absolutely needs to eke out the last few drops of performance out of a system, then it might be worth it.
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