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

[J_Sparrow]

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.

 

[saint19]

Hi J_Sparrow and welcome to THG.

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

2-

"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.

 

[J_Sparrow]

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)

 

[saint19]

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.

 

[J_Sparrow]

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.

 

[saint19]

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.

 

[J_Sparrow]

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...

 

[saint19]

Use N2 and leave the rest in auto.

 

[J_Sparrow]

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...

 

[J_Sparrow]

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?

 

[saint19]

The last number is the tRAS and usually is the sum of the other three numbers. The crash was with LC7 or CL8.

 

[J_Sparrow]

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?

 

[saint19]

RAM problem I think since a CPU problem isn't very commune at this days.

 

[J_Sparrow]

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?

 

[J_Sparrow]

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.

 

[J_Sparrow]

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.

 

[J_Sparrow]

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.

 

[saint19]

More voltage to the RAM and test again.

 

[J_Sparrow]

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?

 

[saint19]

That's the SPD job, reads the speficications of the RAM and set the best configuration (including voltage).

 

[J_Sparrow]

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

 

[saint19]

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)