8-8-8-24 or 9-9-9-27

HI,

I have Kingston KHX1600C9D3/2G (i have 6Gig)

http://www.valueram.com/datasheets/KHX1600C9D3_2G.pdf

i'm overclocking my i7 920 to 3.8GHz on my rampage extreme II Mb.

The guide i'm using explains most stuff well so i know what to do. only probem is the memory. According to what I've read, i should not go above 1.65v as this will damage cpu. But the wording in the descrition of the RAM says:-

"This module has been tested to run
at DDR3-1600MHz at a low latency timing of 9-9-9-27 at 1.7V to 1.9V. The SPD is programmed to JEDEC standard
latency DDR3-1333MHz timing of 9-9-9 at 1.5V."

I have absolutly no idea what the above means? it seems to suggest that I need stupid high voltage settings to get the best out of it? Is it a poor quality RAM?

Currenlty I'm at 3.36GHz, and my timings on RAM are 8-8-8-20, but the guide suggests going for 8-8-8-24.

Any help would be awesome cos I'm totally confused.

Thank you for reading.
21 answers Last reply
More about tomshardware
  1. Hi J_Sparrow and welcome to THG.

    1- Go with 8-8-8-24 and the command rate to 2T.

    2-
    Quote:
    "This module has been tested to run
    at DDR3-1600MHz at a low latency timing of 9-9-9-27 at 1.7V to 1.9V. The SPD is programmed to JEDEC standard
    latency DDR3-1333MHz timing of 9-9-9 at 1.5V."


    That only means that the system identify the operating characterisitics of each memory module installed in the system and run it at that specs.
  2. ok, thanks for the quick reply, i'm over-clocking as we speak.

    OK, i've just now set my BCLK to 181, everything else is on auto, except Vcore, which i set to 1.5v.
    Booted up OK. Used a bench to get all cores to 100%

    Used CPU-Z;-

    Core Speed (on load) is 3800.7MHz
    Multiplier is 21
    QPI Link:- 3258
    Core Voltage:- 1.263v

    And my memory which is on Auto (think this is my problem)
    NB Frequency:- 3076.9MHz
    DRAM Frequency:- 724MHz
    FSB:- 2.8
    Timings:- 9-9-9-24
    Row Refresh Cycle Time:- 74
    1T

    Whats with these timings? They any good or crap.


    -edit- idle is about 35C (for about 25minutes now, therese no reason why this would go higher other then room temp.)

    -edit- running prime95 stress test for 25minutes now. Max temp has been 67C, but mostly hovers between 64C and 66C)
  3. The RAM is currently running at 1448MHz (DDR3) but I think that u can get better performance. Try this times: 7-7-7-21 command rate 2T and 1.65V.
  4. Before I do that, I'd rather not be right on the very edge of safety at 1.65v. You think I can get 8-8-8-something and keep the voltage a bit lower? Reason I mention this is because we are probably talking micro seconds of difference in real world apps and games right? Maybe in a year and a half's time i might get bored and go for 4.2GHz with water cooling and get better memory, but in the mean time what's a good timing that's not borderline suicidal.
  5. U can try the 8-8-8-24 with 1.65V and test it for stability that's the only way to know is can works or not.
  6. OK, I just changed the timings to 8-8-8-24.

    DRAM Frequency is still 724MHz and NB Frequency is still 3076.9MHz. and i'm in windows now. not ran a stress test yet, will do in a minute.

    Whats 'Row Refresh Cycle Time:- 74 clocks' ? (it says tRFC in brackets next to it). Should I change this?

    Also there was no option in bios to change T1, i found a option with something like N1, N2, N3 to choose from...
  7. Use N2 and leave the rest in auto.
  8. ok, will do, just gonna reboot now.

    -edit-

    changed it to N2, and it shows as 2T in CPU-Z thank you. (I only set the DRAM Voltage to 1.64)

    running prime95 now. Just as a thunder storm starts up here in sunny Sunderland...
  9. I crashed. PC just auto rebooted, no beeps or warnings or anything. The only difference was that i was drinking milk, but i don't think thats the problem. Suggestions?
    Core temps were all hovering around 67C

    -edit- ALSO see how some people say 9-9-9- or 8-8-8 or 7-7-7, then lower is better, but what about the 4th number is lower still better? ie, 8-8-8-24 or better to be 8-8-8-20?
  10. The last number is the tRAS and usually is the sum of the other three numbers. The crash was with LC7 or CL8.
  11. ok, so i crashed/reboot on 8-8-8-24
    i switched to 9-9-9-27 and this time everything just froze on the screen so i had to go and press the reset button.
    what now, just switch DRAM timing back to auto?
    these 2 problems sound like RAM problems or CPU problems?
  12. RAM problem I think since a CPU problem isn't very commune at this days.
  13. ok, i noticed that whatever i change the DRAM voltage to in the BIOs and then F10 to save and exit, everything else changes to what I have set... BUT.. if i look in SPD in CPU-Z voltage is 1.50 V in every column. Is that normal?
  14. OK, i found a major problem. I had updated my BIOS, but for some reason its reset to version 1406. I remember messing round with the buttons on the motherboard a few days ago, so i guess i must have done something wrong. i will update it again now.
  15. all updated, had to set everything from scratch in bios again. 920 @ 3.8 and RAM timings and voltage set to auto. Ran prime95 for 25mins with no errors or warnings. It's late now so will mess with RAM tomorrow.
  16. http://valid.canardpc.com/cache/banner/1381530.png

    ok, using the above setting i ran prime95 but it rebooted my pc after about an hour. What do I do next do you think? more voltage for CPU, or more voltage for RAM, currently 1.5v for ram even though i think its running quite 'relaxed' timings?. Temps are not an issue with CPU.
  17. More voltage to the RAM and test again.
  18. i'm changing the DRAM bus Voltage but when i look in SPD on CPU-Z it still only shows as 1.5v, whats the crack with that. I even check the BIOS again and it shows 1.64. press F10 to save and exit, but in windows still only 1.5v. I'm looking at the wrong thing? Have I increased the voltage of the wrong thing?
  19. That's the SPD job, reads the speficications of the RAM and set the best configuration (including voltage).
  20. OK, so you mean it does not matter what DRAM bus voltage I set its gonne auto revert back to 1.5v? I guess there is an option in the BIOS to disable this auto feature and go with my voltage?

    OR if i manually change my settings from 9-9-9-24 to say 9-9-9-27 or 8-8-8-24 will the voltage auto change but keep under my specified amount.

    I appreciate your help by the way. I'd be lost with out it. Also is 9-9-9-24 bad? should i just leave it at this or is my whole system gonna be sluggish because of it?


    or am i looking for baders when i should be looking for pigeons?

    thanks
  21. Change the settings manually and set the voltage to 1.64 and look for the option to disable the SPD (I'm not sure if that option exist or not)
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