Step 2) Optimize Memory Frequency & Uncore
System Memory Multiplier (SPD)
The next step is to find the limit of your memory. In order to do this, we need to prepare you to meet your memory overclocking goal. Start off this step be entering the BIOS and setting the bclock frequency back to 150MHz. Because we have already been through the range of bclocks from 150MHz to 200MHz (or whatever YOU reached), we already know that the bclock and uncore will be stable with these settings. So that effectively allows you to go back through the same range again, changing only the variable of memory, so that you’ll KNOW that that any instability is memory related.
To do that you need to change your System Memory Multiplier (SPD) to a ratio that will allow you to push the blcock back up to your goal, whichout exceeding the memory’s rated speed. Also, manually configure the memory timings according to the manufacturer’s specifications. There will probably be many sub-timings in your BIOS that you could change, but only change the timings specified by the manufacturer, the others leave on auto.
Lets look at the sample systems for an example, for those systems you would configure the System Memory Multiplier (SPD) as follows.
- Sample #1 – set the System Memory Multiplier (SPD) to 8
- Sample #2 – set the System Memory Multiplier (SPD) to 10
- Sample #3 – set the System Memory Multiplier (SPD) to 12
For the sample system #1, the goal is 180MHz bclock, the multiplier is 8, and the memory is rated at DDR3-1333. If we were successful in reaching the 180MHz bclock goal, the memory would be at 180×8 = DDR3-1440. This is about an 8% OC and within the 10% I recommend limiting yourself to for this step.
For the sample system #2, the goal is 200MHz bclock, the multiplier is 10, and the memory is rated at DDR3-2000. If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×10 = DDR3-2000. This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
For the sample system #3, the goal is 200MHz bclock, the multiplier is 12, and the memory is rated at DDR3-2400. If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×12 = DDR3-2400. This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
In the same way, set your multiplier according to your goal, so as to prevent more than a 10% overclock on your memory. As a generalization, memory rated at lower speeds typically has more overclocking potential than higher rated memory. My suggestion for now is to focus on getting the IMC overclocked to the memory’s rated speed (cause remember, the IMC is only rated to run at DDR3-1066).
Instead of overclocking memory, I place a higher value on tightening up timings. Take sample #2 from above, it has DDR3-2000 CAS9 memory. You’ll get better day-to-day performance out of that memory by tightening the timings down to CAS8 level, as opposed to overclocking the speed to DDR3-2100…..not only that, but tightening the timings is almost always easier than increasing the speed. Again, I’m not going to get into detail here because tangible differences on a daily system will not exist.
DRAM voltages
There are two voltages we need to focus on in this section, the QPI/VTT voltage you’ve already become familiar with, and the DRAM voltage itself. QPI/VTT is already high enough to support your bclock and uncore goals, but as we push up the speed of the IMC (which is also part of the uncore), the QPI/VTT voltage may need a bit more. This is especially true if you are running with all 6 memory slots populated, or if you’re using newer 4GB DIMMs, these configurations can put a lot of added stress on the IMC and require extra QPI/VTT voltage to retain stability. For all three sample systems, set the DRAM voltage manually to 1.65V (or 1.66V if 1.65V is not possible).
Testing for highest stable memory frequency
Now start up your selected test program, for example OCCT (RAM) or IntelBurnTest (maximum). Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). Then reboot the system and return to the BIOS.
- If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
- If the test failed, raise the QPI/VTT voltage by 0.0125V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
- You reach the same bclock speed you identified in step one and successfully pass your stability test.
- You reach your maximum safe QPI/VTT voltage (as identified above)
- Raising the QPI/VTT voltage is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
After you have reached your desired goal, be sure to test the overclock with another one hour pass of your selected stability test to ensure the entire uncore is happy with the current configuration. However, I would add one additional stability test at this point, memtest86+. IntelBurnTest and OCCT (RAM) are both very good at identifying IMC and memory error, but neither are as strenuous testing the DRAM modules as memtest. It’s a good way to verify that the memory modules are not defective, and will operate without error. Run at least one pass, or for 1 hour, whichever is greater.
Congratulations! - You now have a relatively stable bclock frequency and memory frequency.
Step 3) Stabilize CPU Frequency
Almost there
The last step in this guide is often the first step for users who run into problems and then troubleshoot for days afterward. Leaving it to the last step makes the task much simpler. You now have the following settings locked in; QPI/VTT voltage, IOH Core voltage, memory voltage, QPI clock ratio, memory ratio, and memory timings. That means when we are looking for our highest CPU frequency, there are only two variables we need to play with: bclock and CPU voltage.
Please start by entering the BIOS and adjust the bclock back down to 150MHz, then adjust the CPU clock ratio as follows.
- Sample #1 – set the CPU clock ratio to x20
- Sample #2 – set the CPU clock ratio to x21
- Sample #3 – set the CPU clock ratio to x23
Load-line calibration (“LLC”)
This actually goes by a few different names, but they are all meant as a means to reduce or prevent v-droop. It does typically ease the overclocking process at the cost of violating Intel’s design specs. However, overclocking in its essence violates Intel’s design specs, so you’re not breaking any new ground with this feature. I highly recommend enabling this feature. High end Gigabyte motherboards have two settings, select “Level 2”. For more insight on the theory of LLC, refer to this excellent explanation at anandtech.com. There was also some real world testing recently; feel free to check out Bobnova’s LLC investigation here.
CPU Vcore
That brings us to the first thing that most users want to play with after powering up their new system for the first time: CPU voltage, aka “Vcore”. As you can see, this is actually one of the last things you should be changing. I would recommend starting at a nice and easy 1.2V. Surprisingly enough, many users are able to achieve very good overclocks with this modest amount of CPU voltage. I would be surprised if sample #1 needed any more than that, sample #2 probably need a bit more, and sample #3 will probably need quite a bit more.
If you are overclocking with power saving features enabled, Gigabyte motherboards will allow you to set the CPU voltage via “Dynamic Vcore” which improves overclocking capabilities while using your power saving features….to unlock this feature; first you have to set the standard Vcore setting to “normal”. Then set the “Dynamic Vcore” setting to +0.05 and increase as directed below.
Testing for your highest stable CPU frequency
Once the operating system has fully loaded, start up RealTemp. Now start up CPU-Z and verify that your overclocked settings have been properly applied, and that you are running at your desired CPU, bclock, and memory frequencies. Each of the sample systems should look like this.
- Sample #1 – CPU = 3000MHz, uncore = 2400MHz, memory = 600MHz
- Sample #2 – CPU = 3150MHz, uncore = 3000MHz, memory = 750MHz
- Sample #3 – CPU = 3450MHz, uncore = 2700MHz, memory = 900MHz
***Note***, if you have SpeedStep (“EIST”) enabled, the CPU speed will fluctuate in CPU-Z and the load changes, please verify values given above WHILE RUNNING YOUR STRESS STEST.
Now start up your selected test program, for example OCCT (CPU) or IntelBurnTest (maximum). Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). Then reboot the system and return to the BIOS.
- If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
- If the test failed, raise the CPU Vcore voltage by 0.025V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
- You reach the same bclock speed you identified in step one and successfully pass your stability test.
- You reach your maximum safe Vcore (as identified above), or maximum safe temperature.
- Raising the Vcore is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
Is it stable?
So, once you find your highest CPU frequency by meeting one of the criteria above, and run OCCT (mix) or IntelBurnTest (maximum) for one hour minimum. I’d like to refer to all this testing as “reasonably stability”. In my experience, the true test of stability is the regular daily operation of your system, doing what you intended it to do.
The reason we use testing programs like OCCT or IntelBurnTest is to simulate a worst case scenario. I have never seen any real world application come close to generating the heat that IntelBurnTest (maximum) generates. But there are a few that can come close to OCCT, like folding or crunching for distributed computing projects, encoding high definition videos, or very heavy multitasking. But even though OCCT or IntelBurnTest (maximum) stress tests tend to generate more heat, they do not always find 100% of instabilities. In my opinion, the ultimate test is to use the system!
Final Words
Well, that about wraps it up. Believe me, there is so much more to overclocking. There are SO MANY settings you can continue to fiddle with, you may have a million questions at this point about all of the settings in the BIOS that we never touched. They’re valid questions, but not meant for this guide. My goal was for this guide to get you 95% of the way in 5% off the time. Hopefully you’re there! The other settings in your BIOS will be needed to get you to 100%….but if I included those things in this guide, it would be 3 times as long, and much more complicated.
Please feel free to comment, and post any questions in the Intel section of the techreation forums. The community is the best resource to continue pushing your system beyond this guide. Post a new thread with a very detailed description of which part of the guide you are having problems with, how far your progressed through the steps, and screenshots to help us understand the problem your encountering if necessary. We will do our best to help you out with any problems you may encounter!
Thanks to Brolloks, noxqzs, Zithras, and many others for their help with this guide.
99 Comments
[...] to get a decent overclock using it either. I got my 920 stable at 4011MHz with it within a night. 3 Step Overclocking Guide – Bloomfield and Gulftown | TechREACTION I'd recommend that to anyone looking to overclock [...]
Hi, I’ve gone through Miah’s steps at the 15 multiplier for an I7 930 up to 200mhz and passed all stability tests using prime95 for 3 loops of a blended test. Do i need to keep testing from 150-200 with each additional multiplier or can i just pick a higher multiplier with a higher bclock freq?
System specs
Asus p6T
i7-930
12 gigs Kingston HyperX 1600 XMP
HD5970
Corsair H100 WATER COOLER
I am retarded (yes here come everyone’s comments on the matter). I missed te text about different board configurations and where gigabyte qpi vtt is different on evga (there it is CPU vtt voltage). I had been increasing qpi pll vcore instead. Let’s see where this goes.
Hmm. Continued on to step two. Can’t get it to post past 160 bclk with dram at 1.65 and the same qpi vtt maxed from the first step of 1.45. Any tips? I have corsair xms3 ram 1600 3×4 gb. Running 9/9/9/24/74/1T timings to achieve 1600.
I did the first step but couldn’t pass bclk of 184 with my qpi vtt maxed at 1.45. I have a 920 D0 and evga x58 board. It wouldn’t pass intelburntest max 3 loops like you suggested. Any tips? Anything else to modify to get it higher before I go to step two (memory)?
Man, I am completely lost, is there anyone with screen shout of a working Asus BIOS and a i7 930 and dual ati cards.
i7 950 4.4GHz
Hey Brian, good questions. The reason is pretty simple….I wanted to make a three step guide, not a four step. Tying the uncore to the bclock in step one (and not to the memory in step two) makes step two possible.
If you don’t tie them together in step one, then in step two, when you reach instability, you will not know whether to increase QPI/VTT voltage, or DRAM voltage
Please feel free to ask more questions, but please do so in the forums where it’ll get more visibility
First: Thank you! Just trying to get into overclocking and your guide is fantastic!!
Second: Why do we lock the desired uncore right away versus increasing it with DRAM later?
I’m following the guide and beginning to overclock bclock. However, if QPI/DRAM voltage is set to 1.2V I can’t post if uncore is set to my desired uncore, but I can post if it’s simply set to double my DRAM frequency. I’m wondering if this is okay for the time being and is something I can adjust later.
Hey mate,
Thankyou very much for this quide im completly new to oc and I was able to understand this after re reading a few times.
Couple of questions..
I forgot to turn off turbo boost during the first 2 steps would this have an effect when doing my bclock setting?
i didnt set my qpi/vtt voltage to max while finding my best bclock so I could have some headroom while doing my ram, turned out I didnt need to touch the voltage while doing memory.
Snould I go back and redo my bclock with the max voltage?
Cheers
Hi, i have the 990x Ans like to oc it to about 4.6 GhZ
Now i read this guide many Tines i ended with one question.
The 990x has an unlocked multiplier. How should i overclock with
leaving THE BCkl and voltages low and turning up just the multiplier?
What more should i do??
Thanks
Kim
Best OC guide. Finally I understand how it works my PC.
)
Best OC’ing guide for Bloomfield I’ve found, used to OC a lot on my old P4 system but got out of touch and this has made the whole process easy and most importantly I actually understand the connection between everything so can fiddle on my own now. Thanks so much!
[...] [...]
Thanks for the kind word Greg. My advice for someone with your HW is to not be too concerned with high bclock frequency….you have the luxury of the unlocked multiplier on your chip and you need to use that to your advantage. The process really doesn’t change at all, except that you can pretty much blow past step 1 and start on step two
Can you start a thread in the forums (in the “Intel” section) and list your full system specs (with full memory configuration details), I’ll catch up with you there :thumb:
Thanks miahallen……..I went “high end” on this build (finally got a job). I also have the 990x CPU (cooled off with a Hydro H80) with 24gb of Dominator GT CAS9 (DDR3-2000).
Should I just follow the settings/instructions in your guide or can you provide any additional instructions/recommedations that should be applied based on these specific components.
I know you can’t possibly provide solutions for every build, but your assistance is putting you that much closer to getting on my Christmas card list.
But honestly……your guide is the bomb!!!! It’s been the easiest one to decipher so far. I’m just glad you are continuing to monitor the posts.
It’s pretty apparent that you have inadvertently have become the “Noobie Savior”.
Hey Crazy Canuck…glad it worked for you
Hey Greg, you should follow the direction for two cards
Nice HW BTW
When considering the IOH Core voltage, should I consider my 2 GTX 590′s to be 4 cards since the both have 2 GPUs?
Thank you so much for this guide, it was so much help. This was my primary overclocking resource but I would also like to point out my other two sources so that it may help noobs like me in the future.
1) http://vip.asus.com/forum/view.aspx?id=20081220191040237&board_id=1&model=P6T+Deluxe&page=1&SLanguage=en-us
2) http://www.overclock.net/intel-cpus/787341-comprehensive-i7-overclocking-guide-explanations-classified.html
I thought overlocking would be easy but even with this guide it took me a couple of days of tweaking to perfect my overclock. My goal was ultra conservative and was to only reach and perfect a 3.6GHz overclock on my i7 920 rig.
My final settings were:
bclk: 180 Mhz
multi: x20
dram freq: x8 (6 Gb Corsair XMS3 1600MHz 8-8-8-24)
Vcore: 1.8750
QPI/dram: 1.2000
DRAM Bus Voltage: 1.50
Max Temp: 70 C (includes ambient temp; CM Hyper 212+)
I was very suprised that I was able to get a stable system lowering this guide’s suggested Vcore from 1.2000 V to 1.8750 V. I was only able to do that after I dropped my DRAM BUS Voltage to 1.50 V from Corsair’s suggested 1.65V. I figured that if my ram was factory tested to run at 1600MHz at 1.65V, i should be able to lower the voltage because my blck only allows for a DRAM speed of 1440MHz and I wasn’t going to try to push my RAM beyond factory specs (again, I’m being ultra conservative). I think lowering the DRAM bus voltage gave me some headroom because where I couldn’t lower the Vcore below 1.2000V before, I could do it afterwards.
Also, why does ASUS lock the minimum QPI/DRAM voltage at 1.2000V?
I was hoping to lower that too but couldn’t because it was locked. I want to have 3.6GHz running as low temp as possible.
My rig passed IBC and memtest86+ running each for over an hour without problems.
I want to thank you again for this awesome guide. I hope there will be guides like this one the next time i need to OC (hopefully not for another 10 years).
Peace
Thanks dawg! Very good info! Good site too!
[...] a 4267MHz at 1.375V. http://valid.canardpc.com/show_oc.php?id=1683337 I followed this guide: http://www.techreaction.net/2010/09/…nd-gulftown/4/ Prior attempts were sloppy and got to around 3.8GHz, but now I have my new WC setup so I'm trying [...]
[...] settings, lots of good guys that will help. Here's a guide someone linked to if you're interested, http://www.techreaction.net/2010/09/…nd-gulftown/3/ good luck [...]
[...] allow you to regain stability.] If you are not familiar with the guide, you can find it here.. http://www.techreaction.net/2010/09/…-and-gulftown/ Good luck!! __________________ _.=4 GHz Overclock Club=.__.=The Core i7 100% Stability Club=._ [...]
[...] you chip has what ittakes to get to 4.5 GHz here is another good guide that will get you there… http://www.techreaction.net/2010/09/…-and-gulftown/ Good luck and have fun!! __________________ _.=4 GHz Overclock Club=.__.=The Core i7 100% [...]
[...] think you should start with a nice overclocking guide before you ask for help. People here will help you, but we will not hold your hand through the [...]
Your questions would be much better suited for the forums where they will be seen more easily and answered.
Please register: http://www.techreaction.net/forums/
Then make a new thread with this information.
Im stucked here: “Sample #2 – set the uncore clock ratio to x20″ with Rampage II Extreme/i7 930. I dont find a place to adjust that.
[...] right, if you feel like trying again, try the method described in this guide: http://www.techreaction.net/2010/09/…-and-gulftown/ I usually always use this methodology and it takes most of the "guess what setting is [...]
Im an idiot, missed the last page. i get it now, find stable VTT voltage at low frequency, then find max CPU frequency at lowest Vcore. Awesome. Great writeup.
This guide doesnt mention Vcore, jsut VTT? So do I just leave the Vcore on auto and adjust the VTT each unsuccessful test?
[...] out this guide And I strongly advise you to not do the quick and dirty method, take the time and do it rght and [...]
This guide esplains very well how the different cpu parts effect each other during oc. You get clocks and voltages for some processors to try with, but more importantly you gain better understanding for later on experimenting and fine tuning the machine.
I really enjoyed this guide, thanks for sharing!
[...] memory speed. For more info I've found Mihallen's guides to be a pretty good starting point. http://www.techreaction.net/2010/09/…-and-gulftown/. You can also click on the Asus link in my sig for a thread with tons of info on overclocking with [...]
[...] cooling on a Asus P6X58D Premium with 12GB G.Skill Ripjaws DDR3-1600 DRAM (3 x 4GB). I followed Miahallen's Guide to Overclocking, and found the BCLK for my board seemed ok up to 210 (overnight IBT test), so I set that as the top [...]
[...] used this guide as a foundation to oc my Core i7 950: http://www.techreaction.net/2010/09/…nd-gulftown/4/ It wants quite a bit more Vcore to get to 4Ghz. I have only messed with a few settings, but I'm [...]
A few observations.
It reported that the highest stable QPI speed is 8000GT/s. Uncore speed should be less than 1:1 ratio to QPI speed, ideally 8:9 ratio. The more 1:1 ratio, the less stable. The nearer you get to 4Ghz QPI speed the less stable as well.
If memory 1600 then Uncore be 3200 and QPI has to be 3600 or higher but not too high or is that unstable too.
[...] it this one? It's the most in depth one I found. I also used this guide for my 930/UD3R. __________________ The Official CM Storm Scout [...]
[...] the actual OCing starts on the 3rd. Though it does do a really good job of explaining everything. http://www.techreaction.net/2010/09/…-and-gulftown/ And if you get any BSODs, this is a quick n' dirty guide that I found a few times on here. But [...]
[...] up to row 64 on my "Attempt Log" spreadsheet following Miahallen's Overclocking guide. Now stable, and following the guide step-by-step has led to vastly superior results than my first [...]
[...] guide here and it works like a charm. Just follow the directions and you should be good to go. http://www.techreaction.net/2010/09/…-and-gulftown/ [...]
[...] I would recommend the slow and steady method as opposed to jumping right in without knowing any info on your chip and how much VTT/Vcore is needed. I recommend using the guide below and start off small and work your self up. 3 Step Overclocking Guide – Bloomfield and Gulftown | TechREACTION [...]
Johnny, your questions would be much better suited for the forums where they will be seen more easily and answered.
Please register: http://www.techreaction.net/forums/
Then make a new thread with this information.
3 GHz core i7-
I am running on an (Intel® Desktop Board DP55KG) motherboard, so I have slots for 4 ram sticks dimms. My question, Is it better to go with a 16 Gig kit DDR3 (4 x 4 GB) or to leave the 4th slot free with a 12 GB kit DDR3 (3 x 4 GB). The difference in cost is $70. And since the 12 GB kit is $230 the increase would be 30%. So, would there be an increase in performance worthy of the increase. I put percentages in there because we all have different opinions on $70, but 30% is the same for all.
[...] you want a good guide by a well respected individual who frequents this board, please read this: http://www.techreaction.net/2010/09/…-and-gulftown/ Everything you will ever need to overclock your 980. [...]
[...] will be : 23xBCLK. default is 133. here is a guide for you, should cover everything you need. http://www.techreaction.net/2010/09/…-and-gulftown/ [...]
Thanks for the comments Johan.
1) My suggestion with QPI, is to set it to the lowest multiplier available (but not “slow mode”). You’re not missing any explicit instruction…..it’s more just the implied suggestion that you quoted.
2) I don’t consider this a variable (the CPU multiplier) because most people start with an intended CPU multiplier at the beginning.
3) My guide could go on with further instruction for fine tuning after step 3, but I think by this time the reader [i]should[/] feel comfortable enough to do that without instruction.
However, going with a lower multiplier and higher blcock would only really be advantageous if done in order to attain a more effective memory speed. There isn’t any other tangible (and even moderate memory speed increases are hardly noticeable day to day) benefit from moderate block increases.
The benefit of keeping the bclock lower on the other hand is fairly tangible in the voltage/temperature/power consumption sense. If those are at all important to you, I’d stick with the 180×21, as opposed to higher bclock/lower multi.
If you have any more questions, please feel free to post in the forums
miahallen, thanks for an excellent tutorial.
1) Excuse me if I’m mistaken (it’s getting quite late here), but you mention on page 4 “You now have the following settings locked in; QPI/VTT voltage, IOH Core voltage, memory voltage, QPI clock ratio, memory ratio, and memory timings.”
When exactly did we “lock in” the QPI clock ratio? Is it on page 2 where you mention “So I never run the QPI clock ratio beyond x36, with the bclock at 200MHz this would result in the QPI running at 7.2GHz which is plenty for anything you might throw at it.”?
If that is the case wouldn’t it be worth reminding readers on page 4 that they actually need to change QPI clock ratio from “Auto” to the one of the three options that is closest to their current BLCK x 36? Because they haven’t been told to change it at any time.
Again, maybe I’m just missing something obvious.
2) Another thing I noticed is on page 4, if I continue where my first quote ended “That means when we are looking for our highest CPU frequency, there are only two variables we need to play with: bclock and CPU voltage.”
Actually three variables, as we’re changing the CPU clock ratio just seconds later (for the first time since we lowered it initially).
3) One thing I miss in this tutorial is advice on what to do if your far from reaching your max stable BCLK with the multiplier suggested, e.g. 21 in example 2. Let’s say you reach your maximum stable CPU speed at 21 x 180 with the Vcore set to it’s max within safe range, but you have initially tested your max BCLK to be 210. Then it might be time to play with different CPU Clock Ratios, or am I mistaken?
[...] right, after following this guide from techreaction (since I had used the other one previously), I now know that other than a few more things to keep [...]
[...] steam is TheCannibal DO NOT use those presets in the mobo. They are horrid. http://www.techreaction.net/2010/09/…-and-gulftown/ Read this. __________________ i7 950 4.4Ghz 1.4v 24/7 i7 950 4.25Ghz 1.3v Mouse: Logitech [...]
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