P67 Sandy Bridge Over Clocking Guide

8/6/2019 P67 Sandy Bridge Over Clocking Guide

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1. P67 Sandy Bridge Overclocking Guide For Beginners

Please note: If you require any kind of assistance,please post in this thread, but make sure that you

add your system specs to your profile (click here tolearn how), and if you want help with overclockingsettings, you need to list all your BIOS settings inthe form of a template - You can find templates formany popular motherboards in the templates


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threadhere. We cannothelp via PM, see here fordetails. It is important that you readALL of thisguide before asking for help as 99% of the things

that people ask are already addressed. Thanks.Welcome to the latest in our highly popular series of beginner's guides, today, we'll be looking at Intel'snewly released Sandy Bridge platform using the P67 chipset. As always, we'll be taking a no-fussapproach to getting the best from your new system.

Intel has both cursed and blessed us overclockers with the Sandy Bridge platform, on one hand, theyhave given us unlocked, and highly overclockable K series CPUs, but on the other hand the rest of the theCPUs have a fixed multiplier - all is not lost though, if you have a locked non-K series Sandy Bridgeprocessor, we can still squeeze a few extra drops of power out of it, so please read this guide and it willbranch you off in the right direction at the appropriate time!

Some people have commented that overclocking is so easy on Sandy Bridge, that a guide isn't required,well, I agree that you can get some fairly high overclocks using the one touch software, or BIOS settings,however, beware, when using things like that, because, although your Vcore (CPU voltage) may look niceand low at idle (0.9v or less), under load, it can be hitting 1.6v or more - Using this guide, you will reachthe same, speeds and higher, but with lower voltage, where possible.

The test set up is as follows:

o Asus P8P67 Deluxeo Intel i7 2600Ko G.SKill PI-S 2x2GB kit @ 1600MHz 8-9-8-24

Before we go any further, it is importantthat youreadthe following paragraph:

Disclaimer: Clunk.org.uk takes no responsibility for any loss or damage incurred as a result ofoverclocking your processor - You need to be aware thatalloverclocking carries a risk of damage. Theamount of risk generally depends on the amount of voltage and heat you subject the processor to, butfailures have been known to happen relatively quickly. Overclocking any CPU will immediately void yourwarranty, so please be aware of this before proceeding.

So, whatare we doingand why?

Well, we are going to take your 2600K from its standard 3.8GHz speed and run it as fast as it'll go with1.35v Vcore*. This increase in speed can make your day to day tasks run quicker and any number

crunching such as folding or video encoding or even Photoshop processing should be more fluid and lesstime consuming.

*You may find that your CPU requires more or less voltage than the one I'm using, it really is impossibleto predict, until you actually start to overclock it, so if it isn't stable using the voltages that I use, try alittle higher and then test again.

If you are using an i3 or i5 processor, you will most likely find that you need less VCore than I use for myi7 2600K, and if this is the case, simply adjust accordingly.


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Why 1.35v Vcore?

The Sandy Bridge PCUs are made from a 32nm process, which means that they are made up from athinner slice of silicon, in theory means that the more voltage and heat you run through them, the moresusceptible they may be to degradation over time, when comparing them to their 45nm and 65nm

predecessors, so we want to keep this to a minimum.

We will not be going for extreme overclocks, that's not what this guide is about, we will be looking for aneasily sustainable, 24/7 overclock with as little voltage as possible. If it's extreme overclocking you want,you shouldn't be needing a guide.

Thingsto know before we getstarted.

Cooling, Coolers,AirflowAndThermal Pastes.

Sandy Bridge CPUs tend to run much cooler than their predecessors, but as you overclock them, and addextra voltage, they can start to get a little toasty, so for any kind of overclocking, I always recommend agood quality CPU cooler - There are lots of great coolers out there and rather than fill up this guide withrecommendations, I'll just say that you will be better off asking on the forums to see which is currentlythe cooler to have.

Along with your cooler, you'll need some thermal paste - again, please ask on the forums for any adviceon choosing your goop as there are loads on the market, ranging from excellent, to decidedly mediocre. Itend to use Arctic Silver Ceramique as it is non conductive and performs well.

Good air flow through your case is essential. If you don't have some kind of circulation of fresh air, yoursystem is going to overheat - We don't want that as excessive heat can cause instability and shorten thelife of some components. If you have a lot of messy wires, it's worth spending a few minutes tidyingthem up and holding them in place with cable ties or velcro straps.

Power Supplies.

I can't stress to you enough, the importance of having a good quality power supply. I'm not saying thatyou should go out and buy the most expensive, or highest wattage unit that you can find, but what I amsaying is to avoid the cheapest units. Always go for a brand you know, and if you are unsure, please askfor help, that'swhatwe are here for.

Whydowe needagoodpowersupply?

You need a good PSU because it is the heart of your system. When you overclock any system, you startto draw a lot more power than you would on a stock system, if the PSU can't deliver the power that isdemanded of it, it may fail - This is where the difference between a good quality PSU and a poor qualityPSU may become apparent. A poor quality PSU, when it fails, will quite often take out other expensive

components, such as your graphics card, or hard drives, or if you are really unlucky, your processor andmotherboard. The bottom line is, get a decent PSU, you'll be glad you did.

Memory.

Things have changed somewhat, regarding memory on Sandy Bridge. On previous platforms, when youincreased the BCLK/FSB, you would automatically increase the memory frequency, so the chances were,that you'd either be under or over the rated speed for your modules.


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Because the BCLK is "fixed" to 100MHz, the memory frequency that you choose in the BIOS, will stay thesame, regardless of the overclock that you end up with (Unless you have a locked CPU, more on thislater), and this is because you have adjusted the CPU's multiplier, instead of the BCLK, this should allbecome less confusing as we progress through the guide, but in short, Sandy Bridge offers the followingmemory frequencies which are selectable, regardless of the CPU speed, but be aware that selecting thetop two whilst running the CPU very fast, will require some extra tweaking, and we will look at that in a

separate article or add on to this guide:

o 800MHzo 1333MHzo 1600MHzo 1866MHzo 2133MHzo 2400MHz (Thisone isforadvancedusersonly)

As with past Intel platforms, there's not a massive amount ofreal worldperformance to be had fromrunning the memory at super high speeds, so my advice, for the best balance between performance is tograb yourself a mid range 1600MHz kit with moderately tight timings, (ask on the forums for details) this

should offer good flexibility when overclocking. Don't worry if you already have your memory, or can'tafford a higher specced kit, the great thing about Sandy Bridge, is that you can set the memory andforget it, so even slower kits will work just fine. All you need to make sure, is that the modules are ratedfor 1.65v or less***.

***See the Troubleshooting and Info section further down for more information on voltages.

Avoid generic, unbranded memory - It can be more trouble than its worth.

Please note that if you plan on a small adjustment of the BCLK on a fixed multi CPU (Non Kversions), or even a K series CPU for that matter, then you may find that your memory doesn't quite fitinto the designated frequency settings listed above, in this case, you'll just have to choose the setting

closest to your memory, and use that. If in doubt, use the next lowest.

Please also note that there is no longer a 2000MHz memory setting on Sandy Bridge. If you have2000MHz memory, you will need to use the 1866MHz setting.

Start with a stable system.

First, update your BIOS to the latest stable version, if unsure what this is, please check themanufacturer's website for more details as this changes regularly.

Before you start overclocking, you need to make sure that your system runs 100% stable at stockspeeds, grab yourself a stress testing program such as Prime95 (or whatever you prefer) and run it for anhour or so and hopefully you won't have any problems - if you do have problems, please ask on theforums for assistance, for the rest of this guide, I will assume that you have already established that yoursystem is stable, and that you have adequate cooling and case ventilation.

Software.

You will need a few pieces of free software, I'll explain how to use these as we go:


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o CPU-Z - This gives us slots of information about the speed and status of thesystem.

o Prime95 - We will be using this for stress testing only.o RealTemp - This gives us a relatively accurate temperature reading for our CPU's

cores.

There are plenty of other excellent, and free pieces of software that you can use if you prefer, LinX is agood stress tester, but be warned, it generates a massive amount of heat and stresses the CPU to thelimit. Because of this, you don't need to run it for as long as you might do when running Prime95.

If you are using an Asus board as I am, then you can use AI Suite to monitor the temps, my testingshowed that the figures reported in AI Suite were comparable to the ones reported in RealTemp andAida64.

OverclockingBackgroundandTheory.

I'll keep this part short because this guide is aimed at beginners, but here's a quote from the originalC2D guide:

Every piece of hardware is unique - No two CPUs, no two sets of RAM, no two motherboards will giveexactly the same results, so keep this in mind when you start overclocking.

You may have a friend that has all the same gear as you, and yet he can overclock his quite a bit higher.Don't worry! - A lot of this is pot luck, some of it is knowing your hardware, and a small part of it ispatience. The rest of it, you'll pick up as you get a feel for how things work.

All of the above still holds true for Sandy Bridge overclocking.

Basically, all we are doing is running the CPU faster than it was intended, we do this by raising theMultiplier and adding a little voltage, it's pretty much as simple as that. For locked CPUs, we raise theBCLK slightly and add a little voltage if required.

What CPU should Iget?

At the time of writing this, there are the following Sandy Bridge CPUs available, if you want guaranteedoverclocking ability, then you need to go for the K versions that I've highlighted in orange in the tablebelow, the rest will only have very limited room for manoeuvre. The 2600K has four cores/eight threads,the 2500K has four cores/four threads. If you use software that can make use of hyperthreading, then gofor the 2600K, if not, the 2500K will be the best choice.


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ImportantTerminology.

Before we start, here's a quick glossary of terms, you can also find out what many acronyms and keywords mean by hovering your mouse over them too. I'll just cover the basics here.

o BCLK (Base Clock) - This is the main clock for the Sandy Bridge platform and itruns at 100Mhz.

o Multipliers (Multis)and Dividers - Sandy Bridge is different in that the baseclock (BCLK) is 100MHz, and everything else, including SATA, PCIe, memory and soon are linked to the BLK, and also run at 100MHz, so adjusting the BCLK ispossible, but you will find that just a few MHz can result in instability - This willvary from CPU to CPU. The point is, the only real divider, as such, is for thememory, and there are several settings available for different speeds of memory,

more on this later. Multipliers play a large role in the overclocking of Sandy BridgeCPUs, as mentioned above.

o VCCSA/VCCIO- On previous platforms (P55/X58) we had the Uncore to describeany part of the CPU that wasn't the actual core, so this would be the memorycontroller, PCIe and so on, Sandy Bridge CPUs have a different architecture, andwith that comes a whole new bucket load of acronyms, VCCSA is the voltage forthe "System Agent", which in a nutshell, is the Sandy Bridge equivalent of Uncore.VCCIO is the I/O voltage for the memory controller. Adjusting the VCCSA andVCCIO voltages can help at higher clocks with higher memory speeds and tightertimings, more on this later.

o IMC - This stands for IntegratedMemory Controller. On previous Intel platforms,the memory controller was on a separate chip known as the North bridge, but with

the latest Lynnfield and Nehalem platforms, and now Sandy Bridge, the memorycontroller is now on die (on the CPU), hence the name IMC.o Hyperthreading - This is a highly complex feature of Intel CPUs, but to simplify,

if you have a four core processor with hyperthreading enabled, a compatibleoperating system will see the four cores plus four virtual cores. If you run softwarethat can take full advantage of this feature, then it can provide some incredibleprocessing speeds, however, the extra speed comes at the cost of increased powerconsumption and generated heat. Try with it enabled and disabled, you may alsofind that you need less Vcore as a result of disabling hyperthreading too.


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o TurboMode - See the explanation below**.o Vcore - This is just another term for the main CPU Voltage, the name may differ

for your motherboard (see the table below).

In the table below, I've listed the main settings that we will be changing during this guide and added aconversion to other manufacturers settings so that people can use the guide with other manufacturer's

motherboards. I will add other manufacturers as I get hold of the boards and settings.

Calculating YourProcessor Speed.

Sandy Bridge is a completely new architecture, and with that comes a new set of overclocking rules andmethods, however, the fundamental practice of overclocking remains the same, we will be addingvoltages and raising frequencies to get us to our required clock speeds.

One of the main differences with the Sandy Bridge platform, is that the BCLK is locked, well actually, itisn't locked as such, but unlike previous platforms (P55, X58) where there was a 133MHz base clock(BCLK) with everything else, such as memory, SATA, running at a set ratio to that BCLK, Sandy Bridgehas a 100MHz BCLK, and everything that is linked to it, also runs at 100MHz, so there is very littleadjustment of the BCLK available. Intel's answer to this is to offer us CPU's with unlocked multipliers - Incase you don't know what a multiplier is, I will keep it simple:

For UnlockedK Series CPUs:

o The unlocked CPUs have a selection of unlocked multipliers, ranging from 16 toaround 57 (if you are lucky!).

o Your BCLK is fixed around 100MHz.o So, your multiplier value (let's say 40 in this case) multiplied by the BCLK value

(100 in this case) = your clock speed of 4000MHz (or 4GHz).

40x100 = 4000MHz. Got it?

Ok, so that is how we calculate our target clock speed. If we wanted to go for a clock speed, other than

4GHz, we would simply adjust the multiplier value to the appropriate value, for example 45 would give us4500MHz (4.5GHz) and so on.

ForLocked Multi CPUs.

o Unfortunately, the non K series CPUs only offer a very limited amount ofoverclocking headroom, and the amount that is attainable, will vary between CPUs,but from my own testing, up to 107 is doable.

o The way we work this out is very similar to the locked one:


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We need to set a few other settings, to keep this as simple as possible, I will listonly the settings thatyou need to change.

AiOverclockTuner - ManualBCLK/PEG Frequency - 100

TurboRatio:

ByAll Cores (CanAdjust InOS) - 40

Memory Frequency - SettoAUTOor 1333MHz fornow - If you are using high speed memory,please still leave this setting low while we find out what the CPU can do.

Next, the DRAM Timings.

You only need to change the top five settings, these are your main memory timings and it is importantthat you set these values to whatever it says on the label on the heat spreaders of your modules, the

DRAM voltage is equally as important too. (See the photo further down).

CASLatency - 8RASto CAS Delay - 9RASPre Time - 8RASACTTime - 24DRAM CommandMode - 1T


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Please note: The memory speed, timings and voltage shown here are just to illustrate what to look for,your memory modules may be something like 1333MHz or 1600MHz and 8-8-8-24 or 9-10-9-28 - usewhatever it says on the label on your modules.

Other frequently asked questions, are:

o "What if my modules are 1.5v or less?"-well, again, set them to whatever itsays on the label.

And,

o "My modules have nothing on the label"-This is quite unusual, so in thiscase, you need to contact the manufacturer, or the retailer that you bought themfrom and obtain the correct details, you may also find the details on the packagingthat the memory came in.

And,

oMy Modules are rated for1.8v, can I use them?-1.8v modules are notsuitable for use in P67 boards unless you run them at 1.65v or less -Keep in mindthat as you are under-voltingthe modules, they willprobablynotrunattheirratedspeeds,sodoingthisisn'trecommendedunlessyouknowwhatyouare doing.

Youmayalsohave wondered,why,onsome memoryspecsthatitshowsahighnumber,andalower

number, forexample ourmemorybelowisratedat1600MHz, butyoucansee onthe labelthatitsays

DDR3-12800,the reason forthisis,the longernumberisthe maximumtheoreticalmemorybandwidthin

Mebibytespersecond,soDDR3-12800 = 12,800 MiB/s,andthe smaller figure 1600MHz inourexample,


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is the memory bus speed.

I'm using these settings for the purposes of this guide:

DRAM CAS#Latency -8 DRAM Clock

DRAM

RAS#to CAS# Delay -9 D

RAM

ClockDRAMRAS#PRETime -8 DRAM Clock

DRAMRAS#ACTTime -24 DRAM Clock

Moving back to the main AI Tweaker page, we need to set some voltages:

Below, I've split the AI Tweaker section into three parts, mainly because it wouldn't all fit on one photo!

Load-Line Calibration-Enabled HighorAuto**

**Anote aboutLoadLine Calibration-Since writing the original i7 guide, it has come to light that in

some circumstances, the enabling of Load Line Calibration may lead to small voltage spikes, especially at

higher Vcore, the other thing is that arguably, you may use slightly more overall power under load than

with it disabled. Given that most of us will not be running at100% load 100%of the time, and the fact

that none of us have seen any damage from using this setting, and that it can be quite useful, I have

decided to leave the setting as enabled. That said, if you prefer, you can disable it, but keep in mind that

you will need to apply more Vcore than you previously did to get stable. Swings and roundabouts!

CPU Voltage -ManualMode

CPU Manual Voltage- 1.12v-In the screen shot below, you can see that next to the CPU Voltage,

there is a value of1.232v, this is what was set on the previous restart, and once you save and exit and


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re-enter the BIOS, your current configuration will be shown, I decided to leave this in so you can see.

DRAM Voltage -Auto-As mentioned earlier, it is important that you set this to whatever it says on the

modules themselves, in the photo, I've left it on auto, but please change it to the correct value for your

modules.

The next screen shot shows the lower part of the AI Tweaker section, there's nothing else to set here,

but I want to mention the CPU Spread spectrum setting as a few people commented on this in previous

guides. On past boards, pre X58, it was advisable to disable spread spectrum as having it enabled it could

cause instability, and leaving it on Auto would often mean that it was enabled by default. That all

changed with X58 and P55, and now the same applies to P67 too, the Auto setting = disabled. Of course,

you can manually set it to disabled to, but there's no need to.


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Once that's all done, save and exit and then boot to windows, if you did everything correctly and it

doesn't boot properly, then you first need a touch more Vcore, and if that doesn't work, then you need to

check out the troubleshooting section of this guide for pointers.

Once we have booted to windows, load up CPU-Z and you should see something like this:


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Now, in case you are wondering why your processor speed is only 1600MHz (1.6GHz), this is because of

Speedstep - It is one of Intel's power saving features and it just lowers the Multiplier (to 16 in this case)

when your processor is idle or not being used much. As soon as the system detects that extra CPU power

is required, it ramps itself up to the required level.

Applying some load to the CPU will result in the CPU-Z screen below, try it for yourself! Also, you may

notice that the voltage is actually slightly higher in the idle screen shot than the loaded one, this is

because of Vdroop****.

****Vdroop, without going into too much detail, is a measure put in place by Intel for a number of

reasons, one being to provide longevity to the power circuits, and another to cut costs by keeping the

PCBs much simpler. What does Vdroop do? Well, let's say that you set 1.3v for your CPU voltage in the

BIOS, you boot to windows and open CPU-Z, and it shows 1.3v as it should, but now stress the CPU and

you will see the voltage drop slightly, some boards are much worse than others. When overclocking, this

isn't ideal as accurate voltages are needed, so the "Loadline Calibration" setting that I mentioned above

is there to reduce the effects of Vdroop, however, it does not stop it completely. As this is a beginner's

guide, I'm going to leave that there as it really is a can of worms!

The same CPU-Z screen shot as above, but with the CPU under load.


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If you select the "Memory" tab in CPU-Z, you should see something like this, although this will depend on

the timings selected for your particular type of RAM. We won't be going into great detail about memory

overclocking in this section, but in case you are wondering why the memory speed (DRAM Frequency) is

only 666.7MHz, it is because DDR stands for Double Data Rate, to find the correct "real" memory speed,

simply double the figure.


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Next, we need to load up our stress testing program, I'm going to use Prime95, the reason for this is that

it will generate a lot of heat and stress the processor more than almost any "real world" application, so

basically, if your CPU can run this, it can run most things. If you do fancy the daddy of all stress tests,

have a look atLinX, this uses Linpack which was originally written to test the performance of CPUs, but

it makes a great stress test too.

Let'sopenPrime95 then!

When you open Prime95 for the very first time, it'll ask you if you want to use the program as it was

originally intended, or just for stress testing, choose the stress testing option.

When the program opens, you should see a screen like this (albeit a lot wider).

We are going to use the default values for this test, so make sure everything looks like the screen-shot

below and then click OK to start the test.


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Now is a good time to open CoreTemp too (or whichever temp monitoring software you decide on). If

you arrange Prime, CPU-Z and CoreTemp on your desktop, it should look something like this (see the

screen-shot below) - You can see that the CPU speed has jumped to 4000MHz (4Ghz) again and your

temps should be holding steady. Your temps may be higher or lower than mine, depending on your

cooling, but at this stage, we shouldn't really be hitting much over 55c.

You can see in this screen shot that there are eight worker threads running in Prime95, this is because

our 2600K has hyperthreading enabled (I mentioned this in post one), if you are running a quad core

CPU with no hyperthreading such as the 2500K, then you will see four threads.


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Leave that running for at least an hour, the actual time that you leave it is entirely up to you, but an hour

should be fine at this stage.

If you see any errors in Prime95 during this time (the green icon will turn red) or you get a BSOD*****

(Blue Screen OfDeath) or your computer restarts without warning, you need to restart the computer,

enter the BIOS and add one more notch of Vcore (CPU Voltage) and then repeat the above steps untilyou can pass your desired stress test without any errors.

*****BSODs-Sometimes (but not always), if you check your BSOD and see a 124or 001 error code,

you can often remedy this by adding a touch more Vcore and repeating the process until you are back to

where you were.

Once an hour or so has passed, you can stop the test by going to the top right hand corner of Prime95-

>Test->Stop Test and you should see something like this.


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That's it, but do you want to go faster? Of course you do!

Next up, 4500MHz (4.5GHz)...

OverclockingTo4500MHz (4.5GHz) @ 1.24v-

1.27v.

Remember how we worked out our processor speed? Of course you do, it was only a few minutes ago!

Using that same calculation, we will need to be going for a Multiplier of 45 and the BCLK is still at

100MHz. So, 100 x 45 = 4500MHz (4.5GHz). Easy!

The drill is the same as before, back to the BIOS and we need to set the 45. We will also need to

increase the Vcore (CPU Voltage) to match our overclock, so, for my CPU, I will need 1.26v, you mayneed a touch more or a touch less.

AiOverclockTuner-Manual

BCLK/PEG Frequency-100

TurboRatio:

ByAll Cores(CanAdjust InOS)-45

Memory Frequency-SettoAUTOor 1333MHz fornow - If you are using high speed memory,

please still leave this setting low while we find out what the CPU can do.

CASLatency - 8

RASto CAS Delay - 9

RASPre Time - 8

RASACTTime - 24

DRAM CommandMode - 1T


CPU Manual Voltage- 1.25v-In the screen shot below, you can see that next to the CPU Voltage,

there is a value of 1.224v, this is what was set on the previous restart, and once you save and exit and

re-enter the BIOS, your current configuration will be shown, I decided to leave this in so you can see.DRAM Voltage -1.5v-Same as last time!


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Once you have set everything as per the settings above, save and exit the BIOS and boot to windows. In

the same way as last time, if the computer fails to load windows, it's likely that you need a touch more

Vcore, so go back, add that and then try again.

Now we have Windows loaded again, it's just a case of repeating what we did earlier with Prime95. Load

it up, along with CPU-Z and CoreTemp and set Prime95 running for around an hour again.


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If your Prime95 run is error free and there are no BSODs or random restarts, then you can move onto the

next step.

At the beginning of the guide, I said that we'd go as high as possible with circa 1.35v, so that's exactly

what we are going to do next...

1. Overclockingto4700MHz (4.7GHz) ~4900MHz (4.9GHz)@ 1.35v.


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Please note: If you require any kind of assistance,please post in this thread, but make sure that youadd your system specs to your profile (click here to

learn how), and if you want help with overclockingsettings, you need to list all your BIOS settings inthe form of a template - You can find templates formany popular motherboards in the templatesthreadhere. We cannothelp via PM, see here fordetails. It is important that you readALL of thisguide before asking for help as 99% of the things

that people ask are already addressed. Thanks.This is the point where we separate the wheat from the chaff! We are going to change our tactics a littlehere, and as we have already set ourselves a voltage limit, lets set the voltage and then see how far wecan go with the multiplier. To do this, enter the next multiplier up, which, if you have been paying

attention, is 46 I was able to reach 48 with full stability at 1.35v, and the settings are below.

As we are getting to quite high clock speeds, we need to keep an eye on the temperatures of our CPU,ideally, we could do with keeping under 65-70C, and this should be fairly easily doable, providing youaren't in a super hot room, and that you have decent airflow through the case and good CPU cooling.

At these speeds, there are a couple of other settings that need our attention, and they are the VCCIO

and VCCSA - These two voltages are a bit of a can of worms at the moment, and there is muchdiscussion about what, if anything is harmful/detrimental to the CPU. From my own personal testing overthe last seven weeks, I found there to be little benefit to be had by upping these voltages much, with oneexception that we may get to later!

Let's get to it then!

Ai Overclock Tuner - ManualBCLK/PEG Frequency- 100

Turbo Ratio:

By All Cores (Can Adjust In OS) - 48

Memory Frequency - Set to AUTO or 1333MHz for now - If you are using high speed memory,please still leave this setting low while we find out what the CPU can do.

CAS Latency- 8RAS to CAS Delay- 9RAS Pre Time - 8RAS ACT Time - 24DRAM Command Mode - 1T


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CPU Voltage -ManualModeCPU Manual Voltage- 1.35v-This is our maximum voltage for this section of the guide.DRAM Voltage -1.5v-Same as last time!

VCCIO Voltage - 1.0v - This voltage is for the memory controller, at this stage, you may not need to

increase it, but by taking it off Auto, you remove the board's ability to over-volt it at high clock speeds,which it does do. Lower clocks are fine on auto.

VCCSA Voltage - 0.9v - This is the System Agent voltage (part of the CPU that isn't the cores), andafter extensive testing, there is no real need to adjust this much, at least not at this stage.


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As with the previous sections, run your chosen stress test for as long as required. For a final test, I'd belooking at 2-3 hours.

Iwanttodo4.8GHz, butmytempsare toohigh-WhatcanIdo?

o The first thing that I would suggest is to check whether or not you really needhyperthreading enabled, check the documentation for your most used software,

even today, many programs do not take advantage of this feature. By disablinghyperthreading, your CPU should run much cooler, and will probably require lessvoltage to get to 4.8GHz.

o Dial down those voltages - During your overclocking escapades, it's all too easy toavoid the time consuming method of raising the voltage one notch at a time, andto increase it in larger increments. Many people tend to leave the voltages oncethey have the CPU stable, and you can sometimes reduce the temps by a fewdegrees.


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o Consider better cooling - Sometimes, simply adding a better fan to your cooler canmake a worthwhile difference, similarly, if you have a tower type cooler that canaccommodate two fans, then a push/pull configuration can also make a reasonabledifference. Decent thermal paste, properly applied is a must.

o As mentioned at the start of this guide, if you haven't already done it, you nowknow why I said to make sure that your case has adequate airflow and is free from

messy wires and clutter. Experiment with fan orientation too, efficient exhaustingof hot air is essential.

I've triedallthe suggestions butitisstillrunningtoohot,isthereanything else Icando?

o Dial down that multiplier, and your Vcore, until you are within usable limits for thecooling you have. Sorry, that's the only thing left!

Summary.

That's all the CPU overclocking out of the way, the final part of our guide focuses on getting the most

from your memory...

1. BringingThe Memory UpToSpeed!So, you have the CPU where you want it, but we still have the memory at Auto/1333, andwe want to be running it as close to its rated speed as possible, just because we can!

This part is relatively straight forward, but you need to test in a slightly different way, and

we'll come to that shortly.

For now, head to the BIOS and find the "Memory Frequency" setting, and change it towhatever your modules are rated for, but do not go higher than that for now. Don't worryif you have, say, 2000MHz modules, you can use the 1866MHz setting instead. If you areon 1333MHz memory, you are already up as far as you can go, so there's no need to followthis part.

We are using 1600MHz modules, so that's what we are going to set.


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Once you have changed the DRAM frequency, save and exit the BIOS, and then boot toWindows, and if it all goes to plan, you should be able to open CPU-Z and see somethinglike this:


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Now, we need to stress test, but this time, we are going to move the emphasis onto thememory, so load up Prime95 again, and when you see the prompt screen to choose thetype of test, choose Large FFTs, and let it run as you would normally. Some people mayprefer other ways of stress testing the memory, and that is fine too, OCCT offers a similarkind of test to Prime, in that it will shift large chunks of data to stress the CPU, memoryand controller.


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This section is going to be quite short, as there is a very limited about of headroom available forBCLK overclocking on Sandy Bridge/P67.

If you have a CPU with a locked multiplier, it may be possible to squeeze a couple of hundredextra Megahertz out of it by using this method.You may have seen a few posts dotted around

the internet claiming that BCLK overclocking will kill your CPU, well according to Asus andGigabyte, this is not the case, and they have no idea why these things are being said. They alsowent on to say that in the months leading up to the Sandy Bridge launch, they tested hundredsof CPUs, but they had a very low failure rate, considering the abuse that they were subjected to.

From my own personal testing, I found that up to 107 BCLK was doable on my CPU before thingsstarted to become unstable, and it required identical voltages to running at the same clock speedusing the multiplier method of overclocking. Some people find that they don't have much roomfor manoeuvre at all, others manage slightly more than 107, and a few fall somewhere in the


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middle at around 105MHz.

Remember in post 1, I showed you how to calculate the clock speed of your CPU? Here it isagain:

Using an example of 103, and the maximum multi available on our locked CPU which, including Turbo, is

38(103x38), this gives us a clock speed of 3914MHz (3.91GHz).

I know that my CPU requires 1.1v for 4Ghz (we can always dial this down later), the rest of the settings

that need to be adjusted are below:

AiOverclockTuner-Manual

BCLK/PEG Frequency-103

TurboRatio:

ByAll Cores (CanAdjust InOS)- 38

Memory Frequency-SettoAUTOor 1333MHz fornow - If you are using high speed memory,

please still leave this setting low while we find out what the CPU can do.

Next, the DRAM Timings.


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You only need to change the top five settings, these are your main memory timings and it is important

that you set these values to whatever it says on the label on the heat spreaders of your modules, the

DRAM voltage is equally as important too.

CASLatency - 8

RASto CAS Delay - 9RASPre Time - 8

RASACTTime - 24

DRAM CommandMode - 1T

Load-Line Calibration-EnabledStandard**

**Anote aboutLoadLine Calibration- Since writing the original i7 guide, it has come to light that in

some circumstances, the enabling of Load Line Calibration may lead to small voltage spikes, especially at

higher Vcore, the other thing is that arguably, you may use slightly more overall power under load than

with it disabled. Given that most of us will not be running at100% load 100%of the time, and the fact

that none of us have seen any damage from using this setting, and that it can be quite useful, I have

decided to leave the setting as enabled. That said, if you prefer, you can disable it, but keep in mind thatyou will need to apply more Vcore than you previously did to get stable. Swings and roundabouts!


CPU Manual Voltage- 1.12v - You may need slightly ore or slightly less than this.

DRAM Voltage -1.5v- Set this to whatever your modules are rated for, check the label on the

modules, if it says 1.65v, then that'/s what you need to set. Modules above 1.65v are not suitable for

Sandy Bridge, so you will need to run them at1.5v, but be aware that they probably will not hit their


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rated speed.

There's nothing else that you need to set, but the final setting on this page called CPU spread Spectrum,

maybe help you to get stable when adjusting the BCLK. My CPU didn't benefit from it, but yours may, so

try with it enabled and disabled if you are struggling to get stable.


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Once you have entered the settings correctly, save and exit, then boot to Windows. If you can't get into

Windows at this stage, it could be for one of two reasons, firstly, your Vcore could be too low, and

secondly, your CPU may not like the BCLK value that you have selected. Firstly, return to the BIOS and

raise the Vcore a notch or two, or even three, and see if you are able to boot successfully, if not, it would

seem that your system does not like BCLK overclocking, and there's really not much else you can do,

apart from try a lower BCLK.

If you have successfully manage to boot to Windows, open CPU-Z and you'll see something like this when

your system is idle:


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And something like this, when the system is under load - The differences in speed are to do with

Speedstep, Intel's power saving features. These work really well on Sandy Bridge when overclocking.

Next, head to the memory tab, and you should see something resembling this, you may notice that the

memory is at an unusual frequency, and this is because the memory bus is linked to the BCLK, when we


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adjust the BCLK, the memory bus automatically adjusts itself too, and in case you are wondering why the

memory speed (DRAM Frequency) is only 666.7MHz, it is because DDR stands for Double Data Rate, to

find the correct "real" memory speed, simply double the figure:

Next, we need to stress test with Primee95, or your preferred stress testing software, OCCT is a good

one, and LinX is the daddy of them all and will generate the most heat. All of them will subject the CPU

to more punishment than pretty much any real world software out there.

Open Prime95 and you'll see this, choose the blend test and run for at least an hour, how long you run it

for is entirely up to you, but a couple of hours is generally fine.


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behaviour is dead or dying memory, if that's the case, you need to see theMemtest instructions below.

TorunMemtest86+ totestyourmemory.

You need to download the ISO of your choice fromhere. I'm using a CD for the guide - Remove all butone module, make sure that you have the correct timings and voltage entered in the BIOS, Boot fromthe CD and you'll see the red and blue DOS style Memtest screen appear, follow the on screeninstructions to change tests and change to test 5 and run that. Leave the test running for around an hourper module, or until you see any errors and it's often a good idea to position a fan over the memory whilethe test is running as it can get quite hot. If the tests are inconclusive, repeat them with all the modulesin different slots, this can often unearth problems with the memory slots.

ToRun HCIMemtest ForWindowstotestyourmemory.

Many people swear by this small utility and it does do a great job at finding problems.Youcandownload HCIMemtesthere. As with Memtest86+, I recommend testing one module at a time.During testing, the computer won't be very responsive, so be aware of that. Leave the test running foraround an hour or until errors show - If you do get errors, don't forget to still test all the remainingmodules as multiple failures can happen.

MiscellaneousInformation.

Below are some snippets of information that I suspect will become frequently asked questions, and willbe updated regularly:

Sandy Bridge has only been around for a short time, but sadly, there is an incredible amount of confusionregarding certain aspects of voltage adjustment. The information below, comes directly from Asus,Gigabyte, Corsair and Intel PMO (Platform Memory Operations), and to the best of my knowledge is100% correct at the time of writing this. Of course, if any new information comes to light, I will updatethis section.

o Sandy Bridge does not demand only 1.5v modules, it will be perfectly happy with1.65v modules too. If someone tries to tell you that you must have 1.5v modules,then they are either trying to sell them to you, or they have been readingmisinformation, or both! Another point to consider here, is that in your BIOS, if youhead to the memory voltage setting, and enter 1.5v, the text will remainwhite/grey, if you enter 1.65v, it will turn yellow, and it isn't until 1.73v that it turnsred, so at the moment, I'd rest assured that 1.65v modules are OK to use, and Ihave had this confirmed by Asus, Gigabyte and Corsair so far, as soon as I hearfrom anyone else, I will update this again.

o Sandy Bridge does not require there to be a maximum of 0.5v between the VDIMMvalue and the VCCIO and VCCSA values when 1.65v voltage modules are used.

o BCLK Overclocking will not murder your CPU or motherboard. There is absolutelyno evidence to support the rumours that adjusting the BCLK upwards on a lockedor unlocked CPU will kill/damage it. What will happen, is that the system willbecome unstable, and you will lose control of things like your hard drive orgraphics card, resulting in instability, corruption or the inability to start up properly.As with any overclocking induced instability, simply reduce the overclock and youwill find that normality resumes - If you have suffered a SATA problem, then youmay have to run your Windows repair console to get the boot loader back.


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Documents

P67 Sandy Bridge Over Clocking Guide