i5 750 Overclocking

[rmcnamara]

My system is as follows:

Gigabyte ga-p55a-ud3
I5 750
gskill F3-12800CL9D-4GBNQ 2x2gb

I have been running this system for months on stock settings. I recently installed watercooling to try some overclocking. I am stable all the way till 170 on pretty much stock voltages. When i go any higher i get a fail to post. I figured it was the processor. I did some reading and decided to lower the memory mult as low it would go to 6.0. The system would boot fine to at least 190, that is where i stopped. Does this sound like the memory is what is blocking me from hitting any higher than 170 on the 8.0 Mult.

That is where i'm at right now. Anything anyone can recommend would be great.

Thanks,
Rob

 

[rmcnamara]

Im sitting at 3.4 170x 20 with memory set to 8. I followed the oc guides i have been reading to lower the mult to the lowest it will go to see how the bclk can go. That is where i'm stuck right now.

 

[Kenmitch]

Im sitting at 3.4 170x 20 with memory set to 8. I followed the oc guides i have been reading to lower the mult to the lowest it will go to see how the bclk can go. That is where i'm stuck right now.

In order to use higher bclock your gonna have to raise the cpu vtt most likely. When you say your using stock voltage that would be auto? Or did you lock it down in bios?

Does your board not let you use the 21x multiplier? Would help alot in the overall overclock if you can enable it.

What settings did you disable in bios?

Maybe quick rundown on your settings would help.

 

[rmcnamara]

Here are my current settings. If any other info is needed let me know

Turbo boost= Disabled
C1E= Disabled
EIST= Disabled
QPI Clock= x32
XMP= Disabled
System Mem mult.= 8.0
Mem Timings=9,9,9,24 CMD 2
Mem freq= 1360
Load Line Calibration= Enabled
CPU VCore= Auto Bios reports 1.29
QPI/VTT= 1.210
DRAM= 1.50 Bios reports 1.56

 

[brencat]

Yep, QPI/VTT voltage is the key to everything. Keep the RAM multi set to the lowest # and the CPU multi to the lowest # and find the max Bclk first. Keep all voltages set to stock except for QPI/VTT which I would START at 1.20 (because you're definitely gonna need more than 1.15v stock anyway if you expect to reach 200 Bclk). Your first POST should be at 9x multi x 150 Bclk using 1.20 QPI/VTT. Go up in 10 Bclk increments till you fail Linpack 20 pass test. Raise QPI/VTT by 0.02v and try again. Rinse, repeat.

Once you've maxed the Bclk, reached 200, or whatever your individual target is, then set your RAM multiplier to whatever gets you closest to the memory's DDR3 rated speed. Example: If you have DDR3-1600, use an 8 RAM multiplier with 200 Bclk = 1600. If you only got to 190 Bclk, then you should still use 8 because if you use the 10 multi, your RAM would be overclocked by a little too much... 8 x 190 = DDR3-1520 vs 10 x 190 = DDR3-1900. Set main 4 timings manually (i.e. 7-9-7-24), and leave everything else on auto. Again, test your setup with Linpack...do 50 passes this time. Raise QPI/VTT if not stable.

Lastly, find max CPU speed. THIS is where we raise vcore, not before. With your max Bclk locked in, QPI/VTT set, and RAM multi set, all that's left now is to raise the multiplier one at a time until you hit your target overclock. You will likely find you'll make it to 3.5ghz on stock vcore, but then the chip will start needing extra. It will likely need substantially higher amounts past 3.8ghz.

A couple other pointers:

- Set QPI clock multiplier to 16x (32x on Gigabyte) and forget about it (default is 18 (36) I think)
- Don't use more than 1.30 - 1.35v QPI/VTT for 24/7 OCing (Intel says max is 1.4v)
- For Linpack test, select "All" memory option to ensure max stress
- Keep temps under 75c loaded.

My method is discussed in more detail here and it is the method I personally used successfully:

http://www.techreaction.net/2010/09/07/3-step-overclocking-guide-lynnfield/2/

On my Gigabyte board, I have Turbo disabled, Load line calibration ON, EIST ON, and CIE and all other C-states disabled. Using EIST is great because instead of directly changing vcore, you can OC with the "Dynamic Vcore" setting. Example...with LLC on, my base vcore is 1.04v. I am using +0.08125v offset in the Dynamic Vcore line, so when CPU loads, it uses 1.12v. When not loaded, it drops multi back to 9x and goes back to base vcore. I believe your board has that feature too.

 

[rmcnamara]

Thanks Brencat. First im only looking to reach 180 or so. I did lower all the multipliers and was able to get to 190 is topped there because im only looking to get up to 180 or so. But as soon as i put the mem mult. to 8 i get the no post. The lowest my QPI goes is 32x. There is one weird thing though. My memory is rated to 1600. But when i look it up on CPU-Z it comes up as PC3-10700.

 

[brencat]

There is one weird thing though. My memory is rated to 1600. But when i look it up on CPU-Z it comes up as PC3-10700.

Yep, it's always going to say it's PC3-10700 on the "SPD" tab, but look on the "Memory" tab of CPUZ...it should say DRAM frequency "720 mhz" if you're at 180 Bclk, or "760 mhz" if you're at 190 Bclk. Next line FSB: DRAM will read 2:8 if using the 8 multiplier.

Fail to post on Bclk tests or RAM tests (assuming you've got your CPU multiplier to the lowest setting) is indicative of too low QPI/VTT voltage. Give it a notch more...don't be afraid to use 1.25v.

 

[rmcnamara]

Thank you. I am going to try that tomorrow. And report back.if it is the memory what would you suggest as a good replacement that would get me to where I'm looking to be.

Rob

 

[brencat]

Thank you. I am going to try that tomorrow. And report back.if it is the memory what would you suggest as a good replacement that would get me to where I'm looking to be.

Rob

Well, you're only at 1.21v QPI/VTT per your earlier post so let's not entertain faulty memory just yet, especially since we're talking 180+ Bclk as your target.

 

[rmcnamara]

Well i got back at it today. I was able to Run the system all the way up to:
190x15 Mem vtt at 1.2 multiplier of 8.0 Got the memory to pass 1440. I raised the ram voltage to 1.63 from the default of 1.5. Cpu voltage says it is at 1.36.

Well now that i have gotten here where would be a good place to go from here?

 

[brencat]

Well i got back at it today. I was able to Run the system all the way up to:
190x15 Mem vtt at 1.2 multiplier of 8.0 Got the memory to pass 1440. I raised the ram voltage to 1.63 from the default of 1.5. Cpu voltage says it is at 1.36.

Well now that i have gotten here where would be a good place to go from here?

Can you clarify a few things...

What QPI/VTT are you able to stably run 180 Bclk, and then 190 Bclk? Stable as in 50 passes Linpack AND 1 hour OCCT Large Data Set test?

Secondly, you say you got mem to pass at DDR3-1440 which would be = 180 Bclk using the 8 multiplier. Did it pass the afformentioned Linpack 50 passes AND 1 hour OCCT? How about at 190 Bclk x 8 = DDR3-1520 ?

If you failed any of the above, you need to raise QPI/VTT BEFORE adding any more vDIMM. Those sticks you have are rated for 9-9-9-24 @ 1.50v, yes? I would see if you can get away with 1.60v or less, preferably 1.55v or 1.575v.

 

[rmcnamara]

Well Right now it is running at 180x 20 QPI/VTT is at 1.25 vcore at 1.2. I have run 5 passes of the burn test with success. I will be running it for 50 passes overnight see how it fares for a real stability test.

The memory did 5 passes @1520. Running it overnight will be the true test. The memory is rated at 9-9-9-24 2t @1.5

Reading all the way through the guide really helped a lot. And the hints you gave me last night.

 

[brencat]

Well Right now it is running at 180x 20 QPI/VTT is at 1.25 vcore at 1.2.

Reading all the way through the guide really helped a lot. And the hints you gave me last night.

Happy to help. So you are using 1.25v QPI/VTT and 1.20v CPU vcore currently? In your last post you said CPU vcore was 1.36v... please clarify. Does the "Auto" setting give you 1.20v or 1.36v in CPUZ under load with LLC on?

Here is what mine looked like... note CPUZ main screen upper left while under load:

http://img835.imageshack.us/img835/7519/i576038ghzloaded.png

 

[rmcnamara]

I'm sorry I should have been more clear. I had vcore on auto with LLC on which gave me 1.36. My temps were a little high so I set it to 1.2 with LLC off. That is where I'm at now. Temps are much better now 51c load

 

[brencat]

Best thing would be to change CPU vcore setting from Auto to "Normal". Then reboot and go back into bios and see what the M.I.T. shows as your base vcore. Since you have a Gigabyte board, setting CPU vcore to Normal will give you access to Dynamic Vcore line item. You can add vcore using that with EIST enabled. Whatever you feel comfortable doing.

I just find it hard to believe that your vcore on Auto was 1.36v before without you having the mobo set for any kind of preset overclocking feature. That happened to me when I first got this setup...I set the RAM to the 'XMP profile' and the board set my CPU vcore to 1.28v along with a few other adjustments! Quickly realized that after I saw my temps in the high 60s and cleared CMOS and started over. I set everything manually after that.