P67 Sandy Bridge Overclocking Guide For Beginners

[Clunk]

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide 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's newly released Sandy Bridge platform using the P67 chipset. As always, we'll be taking a no-fuss approach to getting the best from your new system.

Intel has both cursed and blessed us overclockers with the Sandy Bridge platform, on one hand, they have given us unlocked, and highly overclockable K series CPUs, but on the other hand the rest of the the CPUs have a fixed multiplier - all is not lost though, if you have a locked non-K series Sandy Bridge processor, we can still squeeze a few extra drops of power out of it, so please read this guide and it will branch 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 nice and low at idle (0.9v or less), under load, it can be hitting 1.6v or more - Using this guide, you will reach the same, speeds and higher, but with lower voltage, where possible.

The test set up is as follows:

• Asus P8P67 Deluxe
• Intel i7 2600K
• G.SKill Ripjaws X 2133MHz Kit, running @ 1600MHz 8-9-8-24

Before we go any further, it is important that you read the following paragraph:

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

So, what are we doing and why?

Well, we are going to take your 2600K from its standard 3.8GHz speed and run it as fast as it'll go with 1.35v 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 less time consuming.

*You may find that your CPU requires more or less voltage than the one I'm using, it really is impossible to predict, until you actually start to overclock it, so if it isn't stable using the voltages that I use, try a little 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 my i7 2600K, and if this is the case, simply adjust accordingly.

Why 1.35v Vcore?

The Sandy Bridge PCUs are made from a 32nm process, which means that they are made up from a thinner slice of silicon, in theory means that the more voltage and heat you run through them, the more susceptible 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 an easily sustainable, 24/7 overclock with as little voltage as possible. If it's extreme overclocking you want, you shouldn't be needing a guide.

Things to know before we get started.

Cooling, Coolers, Airflow And Thermal Pastes.

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

Along with your cooler, you'll need some thermal paste - again, please ask on the forums for any advice on choosing your goop as there are loads on the market, ranging from excellent, to decidedly mediocre. I tend 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, your system is going to overheat - We don't want that as excessive heat can cause instability and shorten the life of some components. If you have a lot of messy wires, it's worth spending a few minutes tidying them 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 that you should go out and buy the most expensive, or highest wattage unit that you can find, but what I am saying is to avoid the cheapest units. Always go for a brand you know, and if you are unsure, please ask for help, that's what we are here for.

Why do we need a good power supply?

You need a good PSU because it is the heart of your system. When you overclock any system, you start to draw a lot more power than you would on a stock system, if the PSU can't deliver the power that is demanded of it, it may fail - This is where the difference between a good quality PSU and a poor quality PSU 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 and motherboard. 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 you increased 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.

Because the BCLK is "fixed" to 100MHz, the memory frequency that you choose in the BIOS, will stay the same, regardless of the overclock that you end up with (Unless you have a locked CPU, more on this later), and this is because you have adjusted the CPU's multiplier, instead of the BCLK, this should all become less confusing as we progress through the guide, but in short, Sandy Bridge offers the following memory frequencies which are selectable, regardless of the CPU speed, but be aware that selecting the top 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:

• 800MHz
• 1333MHz
• 1600MHz
• 1866MHz
• 2133MHz
• 2400MHz (This one is for advanced users only)

As with past Intel platforms, there's not a massive amount of real world performance to be had from running the memory at super high speeds, so my advice, for the best balance between performance is to grab 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't afford a higher specced kit, the great thing about Sandy Bridge, is that you can set the memory and forget it, so even slower kits will work just fine. All you need to make sure, is that the modules are rated for 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 K versions), or even a K series CPU for that matter, then you may find that your memory doesn't quite fit into 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 have 2000MHz 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 the manufacturer'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 stock speeds, grab yourself a stress testing program such as Prime95 (or whatever you prefer) and run it for an hour or so and hopefully you won't have any problems - if you do have problems, please ask on the forums for assistance, for the rest of this guide, I will assume that you have already established that your system 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:

• CPU-Z - This gives us slots of information about the speed and status of the system.
• Prime95 - We will be using this for stress testing only.
• 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 a good stress tester, but be warned, it generates a massive amount of heat and stresses the CPU to the limit. 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 testing showed that the figures reported in AI Suite were comparable to the ones reported in RealTemp and Aida64.

Overclocking Background and Theory.

I'll keep this part short because this guide is aimed at beginners, but here's a quote from the original C2D guide:

Every piece of hardware is unique - No two CPUs, no two sets of RAM, no two motherboards will give exactly 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 is patience. 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 the Multiplier and adding a little voltage, it's pretty much as simple as that. For locked CPUs, we raise the BCLK slightly and add a little voltage if required.

What CPU should I get?

At the time of writing this, there are the following Sandy Bridge CPUs available, if you want guaranteed overclocking ability, then you need to go for the K versions that I've highlighted in orange in the table below, 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 go for the 2600K, if not, the 2500K will be the best choice.




Important Terminology.

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

• BCLK (Base Clock) - This is the main clock for the Sandy Bridge platform and it runs at 100Mhz.
• Multipliers (Multis) and Dividers - Sandy Bridge is different in that the base clock (BCLK) is 100MHz, and everything else, including SATA, PCIe, memory and so on are linked to the BLK, and also run at 100MHz, so adjusting the BCLK is possible, but you will find that just a few MHz can result in instability - This will vary from CPU to CPU. The point is, the only real divider, as such, is for the memory, 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 Bridge CPUs, as mentioned above.
• VCCSA/VCCIO - On previous platforms (P55/X58) we had the Uncore to describe any part of the CPU that wasn't the actual core, so this would be the memory controller, PCIe and so on, Sandy Bridge CPUs have a different architecture, and with that comes a whole new bucket load of acronyms, VCCSA is the voltage for the "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 and VCCIO voltages can help at higher clocks with higher memory speeds and tighter timings, more on this later.
• IMC - This stands for Integrated Memory 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 memory controller is now on die (on the CPU), hence the name IMC.
• Hyperthreading - This is a highly complex feature of Intel CPUs, but to simplify, if you have a four core processor with hyperthreading enabled, a compatible operating system will see the four cores plus four virtual cores. If you run software that can take full advantage of this feature, then it can provide some incredible processing speeds, however, the extra speed comes at the cost of increased power consumption and generated heat. Try with it enabled and disabled, you may also find that you need less Vcore as a result of disabling hyperthreading too.
• Turbo Mode - See the explanation below**.
• 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 a conversion 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 Your Processor Speed.

Sandy Bridge is a completely new architecture, and with that comes a new set of overclocking rules and methods, however, the fundamental practice of overclocking remains the same, we will be adding voltages 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, it isn'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 Bridge has a 100MHz BCLK, and everything that is linked to it, also runs at 100MHz, so there is very little adjustment of the BCLK available. Intel's answer to this is to offer us CPU's with unlocked multipliers - In case you don't know what a multiplier is, I will keep it simple:

For Unlocked K Series CPUs:

• The unlocked CPUs have a selection of unlocked multipliers, ranging from 16 to around 57 (if you are lucky!).
• Your BCLK is fixed around 100MHz.
• 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 us 4500MHz (4.5GHz) and so on.

For Locked Multi CPUs.

• Unfortunately, the non K series CPUs only offer a very limited amount of overclocking headroom, and the amount that is attainable, will vary between CPUs, but from my own testing, up to 107 is doable.
• The way we work this out is very similar to the locked one:
• Using the example of 107 that I mentioned above, and the maximum multi available on our locked CPU which, including Turbo, is 38 (107x38), this gives us a clock speed of 4066MHz (4.06GHz).

**Turbo mode is quite a complex feature, and the way we use it on Sandy Bridge for overclocking is quite different from before. A simple explanation of this would be that rather than overclocking the CPU's multi, we are actually overclocking the turbo ratio, so for example, our default clock speed is 3800MHz on our 2600K with Turbo, or 3400MHz without, so if we increase the Turbo ratio, we increase our maximum clock speed too - It's easy to work out, whatever figure you enter for the Turbo ratio, simply multiply that by the base clock value (which will be 100MHz) and that will give you your clock speed in MHz.

Keep all that in mind, the same rules apply when we are overclocking too.

Familiarise Yourself With The BIOS.

When you start overclocking, it's important that you familiarise yourself with your motherboard's BIOS. Just spend some time getting to know some of the basics and this will help you when you move to the more advanced things later.

For the purposes of this guide, I'll assume that you know how to enter the BIOS, make changes and save and exit.

Next, getting started...

Index.

1. Intro, Overclocking Information And index
2. Getting Started And Overclocking To 4GHz
3. Overclocking to 4.5GHz @ 1.24v ~ 1.27v
4. Overclocking to 4.7Ghz ~ 4.9GHz @ 1.35v
5. Bringing Up The Memory Speed!
6. Overclocking With A Locked Sandy Bridge CPU
7. Troubleshooting And Handy Info Section.
8. Conclusion.

This guide is proudly sponsored by G.Skill:



G.SKill are one of the few memory manufacturers out there that cater to the PC enthusiast, and produce memory that performs well, and doesn't cost a fortune, so, we are proud to have them sponsor this guide!

We are using the Ripjaw X modules throughout the guide (although at a reduced speed), and you can find our review of them here.

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide before asking for help as 99% of the things that people ask are already addressed. Thanks.

[Clunk]

Getting Started And Overclocking to 4GHz.

(People with locked CPUs click here)

Restart your PC and enter the BIOS, head for the "AI Tweaker" section (or the equivalent on your board). First up, we are going to change the turbo ratio to give us 4GHz. Now, if you remember earlier, I showed you how to work this out?

Here it is again:

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).

We need to set a few other settings, to keep this as simple as possible, I will list only the settings that you need to change.

Ai Overclock Tuner - Manual
BCLK/PEG Frequency - 100

Turbo Ratio:

By All Cores (Can Adjust In OS) - 40

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.



Next, the DRAM Timings.

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. (See the photo further down).

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



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 - use whatever it says on the label on your modules.

Other frequently asked questions, are:

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

And,

• "My modules have nothing on the label" - This is quite unusual, so in this case, you need to contact the manufacturer, or the retailer that you bought them from and obtain the correct details, you may also find the details on the packaging that the memory came in.

And,

• My Modules are rated for 1.8v, can I use them? - 1.8v modules are not suitable for use in P67 boards unless you run them at 1.65v or less - Keep in mind that as you are under-volting the modules, they will probably not run at their rated speeds, so doing this isn't recommended unless you know what you are doing.

You may also have wondered, why, on some memory specs that it shows a high number, and a lower number, for example our memory below is rated at 1600MHz, but you can see on the label that it says DDR3-12800, the reason for this is, the longer number is the maximum theoretical memory bandwidth in Mebibytes per second, so DDR3-12800 = 12,800 MiB/s, and the smaller figure 1600MHz in our example, 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 DRAM Clock
DRAM RAS# PRE Time - 8 DRAM Clock
DRAM RAS# ACT Time - 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 High or Auto**

**A note about Load Line 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 at 100% 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 - Manual Mode
CPU Manual Voltage - 1.12v - In the screen shot below, you can see that next to the CPU Voltage, there is a value of 1.232v, 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 - 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.



**A note about PLL Overvoltage. It has come to my attention that since writing this guide, the behaviour of the "auto" setting for PLL Overvoltage has changed, previously auto = disabled, but it appears that Asus have made it so that the auto setting will enable PLL Overvoltage at around 4400MHz~4500MHz onwards, so for this reason, please make sure that for all parts of this guide, this setting is manually set to Disabled.

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:



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.



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.



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 at LinX, this uses Linpack which was originally written to test the performance of CPUs, but it makes a great stress test too.

Let's open Prime95 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.



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.



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 Of Death) 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 until you can pass your desired stress test without any errors.

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



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

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

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide before asking for help as 99% of the things that people ask are already addressed. Thanks.

[Clunk]

Overclocking To 4500MHz (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 may need a touch more or a touch less.

Ai Overclock Tuner - Manual
BCLK/PEG Frequency - 100

Turbo Ratio:

By All Cores (Can Adjust In OS) - 45

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

CPU Voltage - Manual Mode
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!







**A note about PLL Overvoltage. It has come to my attention that since writing this guide, the behaviour of the "auto" setting for PLL Overvoltage has changed, previously auto = disabled, but it appears that Asus have made it so that the auto setting will enable PLL Overvoltage at around 4400MHz~4500MHz onwards, so for this reason, please make sure that for all parts of this guide, this setting is manually set to Disabled.

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.



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...

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide before asking for help as 99% of the things that people ask are already addressed. Thanks.

[Clunk]

Overclocking to 4700MHz (4.7GHz) ~ 4900MHz (4.9GHz)@ 1.35v.

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide 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 little here, and as we have already set ourselves a voltage limit, lets set the voltage and then see how far we can 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 you aren'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 much discussion about what, if anything is harmful/detrimental to the CPU. From my own personal testing over the last seven weeks, I found there to be little benefit to be had by upping these voltages much, with one exception that we may get to later!

Let's get to it then!

Ai Overclock Tuner - Manual
BCLK/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 - 8
RAS to CAS Delay - 9
RAS Pre Time - 8
RAS ACT Time - 24
DRAM Command Mode - 1T

CPU Voltage - Manual Mode
CPU 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), and after extensive testing, there is no real need to adjust this much, at least not at this stage.







**A note about PLL Overvoltage. It has come to my attention that since writing this guide, the behaviour of the "auto" setting for PLL Overvoltage has changed, previously auto = disabled, but it appears that Asus have made it so that the auto setting will enable PLL Overvoltage at around 4400MHz~4500MHz onwards, so for this reason, please make sure that for all parts of this guide, this setting is manually set to Disabled. (Thanks to Praz for this info)

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



I want to do 4.8GHz, but my temps are too high - What can I do?

• The first thing that I would suggest is to check whether or not you really need hyperthreading enabled, check the documentation for your most used software, even today, many programs do not take advantage of this feature. By disabling hyperthreading, your CPU should run much cooler, and will probably require less voltage to get to 4.8GHz.
• Dial down those voltages - During your overclocking escapades, it's all too easy to avoid the time consuming method of raising the voltage one notch at a time, and to increase it in larger increments. Many people tend to leave the voltages once they have the CPU stable, and you can sometimes reduce the temps by a few degrees.
• Consider better cooling - Sometimes, simply adding a better fan to your cooler can make a worthwhile difference, similarly, if you have a tower type cooler that can accommodate two fans, then a push/pull configuration can also make a reasonable difference. Decent thermal paste, properly applied is a must.
• As mentioned at the start of this guide, if you haven't already done it, you now know 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 exhausting of hot air is essential.

I've tried all the suggestions but it is still running too hot, is there anything else I can do?

• Dial down that multiplier, and your Vcore, until you are within usable limits for the cooling 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...

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide before asking for help as 99% of the things that people ask are already addressed. Thanks.

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Bringing The Memory Up To Speed!

So, you have the CPU where you want it, but we still have the memory at Auto/1333, and we 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 to whatever your modules are rated for, but do not go higher than that for now. Don't worry if you have, say, 2000MHz modules, you can use the 1866MHz setting instead. If you are on 1333MHz memory, you are already up as far as you can go, so there's no need to follow this part.

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



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



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



If, for some reason, Prime95 fails, then there are a few avenues to explore. The most common reason for failure at this point is if you have very fast modules, or modules with extremely tight timings, or both of the above. The remedy for this, is to increase the VCCIO voltage slightly, in small increments, testing in-between until stable. If you are running a high CPU clock speed, and very fast modules (let's say 7-8-7-24 2133MHz for example), you may find that you need a fair old slug of VCCIO voltage to get stable, and this brings me to dilemma number one!

On Sandy Bridge, the CPU clock speed is king for the vast majority of tasks, and memory performance comes a distant second, so, when plying your CPU with VCCIO voltage to get the memory speed right for those expensive modules, ask yourself if the performance benefits are worth it, or are you better off settling for a slightly lower memory speed, in favour of a higher CPU clock speed and lower voltage.

My personal feeling is that I would prefer to use less voltage, and have a faster CPU for my day to day tasks, but they key thing here, is that everyone's requirements are different, different software and games will produce different results, so the choice is down to you.

So, there you have it, you now have the fastest quad core CPU on the planet, running 26% faster! That's where we are going to leave the beginners part of this guide, but stay tuned for a 5Ghz+ add on for advanced users.

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Overclocking With A Locked Sandy Bridge CPU.



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

If you have a CPU with a locked multiplier, it may be possible to squeeze a couple of hundred extra 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 and Gigabyte, this is not the case, and they have no idea why these things are being said. They also went on to say that in the months leading up to the Sandy Bridge launch, they tested hundreds of 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 things started to become unstable, and it required identical voltages to running at the same clock speed using the multiplier method of overclocking. Some people find that they don't have much room for manoeuvre at all, others manage slightly more than 107, and a few fall somewhere in the middle at around 105MHz.

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

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:

Ai Overclock Tuner - Manual
BCLK/PEG Frequency - 103

Turbo Ratio:

By All Cores (Can Adjust In OS) - 38

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.



Next, the DRAM Timings.

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.

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



Load-Line Calibration - Enabled Standard**

**A note about Load Line 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 at 100% 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 - Manual Mode
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 at 1.5v, but be aware that they probably will not hit their 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.



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:



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 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.



So, you have stressed for a couple of hours and everything is running well, but you want to go a little bit higher, so what can we do?

Well, simply head back to the BIOS, and up the BCLK by one notch, and repeat the process, it really is that simple. How much you are able to increase the BCLK by, will largely depend on your CPU and motherboard.

One other item that you may need, that I didn't mention in the first post, is your Windows disk. While trying to establish your highest BCLK, you may find that your Windows install goes belly up and you are unable to boot, this means that you've gone too far, so go back to the BIOS, drop the BCLK back to stock and set the BIOS to boot from your windows disk, choose "repair my computer" and let it do its thing, should take a few minutes and you'll be back to normal again. This time, use a slightly lower BCLK and test again.

You should now head over to the memory section of the guide!

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 to learn how), and if you want help with overclocking settings, you need to list all your BIOS settings in the form of a template - You can find templates for many popular motherboards in the templates thread here. We cannot help via PM, see here for details. It is important that you read ALL of this guide before asking for help as 99% of the things that people ask are already addressed. Thanks.

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Troubleshooting And Handy Info Section.

From time to time, you may get to a point where the PC wont post after you have done a "bad overclock" and it appears to be either dead, or you just get a black screen. Don’t panic yet! There are a few things you can try.

• Unplug the PSU at the back or at the wall. Often, just doing this for a few seconds is enough to let the motherboard reset itself, especially on a board like the P8P67 Deluxe, which recovers well from a bad overclock. If that doesn’t work, on to step 2.

• With the PSU unplugged, locate the CMOS clear jumper (see your manual for this) and move it into the "clear" position and leave it for a few minutes and remove the motherboard battery. While it is clearing, press the on/off switch on the case, this will help to discharge any electricity left in the capacitors on the motherboard. If this doesn’t work, on to the third step.

• Repeat the second step above, this time leave the CMOS jumper in the "clear" position for a few hours, overnight if possible and also remove the RAM and make sure the battery is removed. If that doesn't work, see the next step below.

• Remove the CPU and power on the board, as you would if there was a CPU in there, leave it running for about 30-60 seconds. Reset the CMOS again, as mentioned in the second step above. Hopefully you should be OK now.

• If you are still struggling to get stable, another thing you can try, is to swap the RAM into different slots. For example, change the module in slot one for slot three and so on, sometimes this can work.

• Your Multi is showing as 16x in CPU-Z, when it should be higher (34x etc), and your CPU speed is showing as much lower than it should be! - Go into the BIOS and under the advanced CPU settings, disable EIST/SPEEDSTEP to fix this, however, for the purposes of this guide, I recommend you leave these settings enabled. They should work fine as they are and save you electricity!

• Sometimes my PC won't boot and it just hangs at a black screen - Many boards have a problem with AHCI and USB flash drives/USB hard drives. The only workaround I've found is to remove the USB drive immediately after using it and to avoid leaving it plugged in between restarts. Another culprit of this kind of behaviour is dead or dying memory, if that's the case, you need to see the Memtest instructions below.

• Wake Up problems - Make sure that you have changed the PLL Overvoltage from auto to disabled if using a later BIOS. Earlier BIOSes meant that Auto = disabled, later BIOSes meant that PLL Overvoltage was automatically enabled around 4400MHz-4500MHz.

To run Memtest86+ to test your memory.

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

To Run HCI Memtest For Windows to test your memory.

Many people swear by this small utility and it does do a great job at finding problems. You can download HCI Memtest here. 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 for around an hour or until errors show - If you do get errors, don't forget to still test all the remaining modules as multiple failures can happen.

Miscellaneous Information.

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

Sandy Bridge has only been around for a short time, but sadly, there is an incredible amount of confusion regarding 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 is 100% correct at the time of writing this. Of course, if any new information comes to light, I will update this section.

• Sandy Bridge does not demand only 1.5v modules, it will be perfectly happy with 1.65v 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 reading misinformation, or both! Another point to consider here, is that in your BIOS, if you head to the memory voltage setting, and enter 1.5v, the text will remain white/grey, if you enter 1.65v, it will turn yellow, and it isn't until 1.73v that it turns red, so at the moment, I'd rest assured that 1.65v modules are OK to use, and I have had this confirmed by Asus, Gigabyte and Corsair so far, as soon as I hear from anyone else, I will update this again.
• Sandy Bridge does not require there to be a maximum of 0.5v between the VDIMM value and the VCCIO and VCCSA values when 1.65v voltage modules are used.
• BCLK Overclocking will not murder your CPU or motherboard. There is absolutely no evidence to support the rumours that adjusting the BCLK upwards on a locked or unlocked CPU will kill/damage it. What will happen, is that the system will become unstable, and you will lose control of things like your hard drive or graphics card, resulting in instability, corruption or the inability to start up properly. As with any overclocking induced instability, simply reduce the overclock and you will find that normality resumes - If you have suffered a SATA problem, then you may have to run your Windows repair console to get the boot loader back.

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Conclusion.



That's about it for the moment as far as overclocking your Sandy Bridge CPU is concerned, we've covered multiplier overclocking, BCLK overclocking and memory optimisation. If you have an unlocked CPU, you can even try and combine multiplier overclocking with BCLK overclocking, you can often sneak an extra few MHz by doing this, but as always, your mileage may vary, and have your Windows disc handy, in case it all goes pear shaped!

One thing that I would like to mention, and it has been the source of much debate accross many forums over the last couple of weeks, and that is the subject of safe voltages. The short answer is that there are no 100% safe voltages over and above stock, yes there are recommended limits, but as we are driving our CPU way past the speeds at which they are designed to run, then we need to be aware that there can be failures, there can be degradation in things like memory controllers too, but the main thing to keep in mind, is that Intel are keen to push the overclocking side of their K series processors, and for them to do that, they need to offer some kind of warranty. To offer a warranty, they need to bring a product that is robust and can handle a fair amount of abuse, from what I can gather from around seven weeks of testing (at the time of writing this), they have done just that, my CPU has been subjected to well over 1.7v, it has been up to the 57 multi, although it struggled to get into windows, it has been up to 110 BCLK and has had 1.6v on both the VCCIO and VCCSA, and is still able to run LinX at 5200MHz with the memory at 1866MHz 6-7-6-24. In my opinions, the failures that have been reported, and I know of only two that have been confirmed, could easily be down to something as simple as a bad PSU, or motherboard. I guess, what I'm getting at here, is that you are buying a product designed for overclocking, so overclock it, don't worry about it, and enjoy it!

As always, if you have any questions about anything in this guide, please reply to this thread and we'll do our best to help. If you do require assistance, please make sure that you add your full system specs to your profile (see my sig for details), and have a BIOS template ready if we need your settings.

Have fun, and be sure to let us know how you get on!

This guide is proudly sponsored by G.Skill:

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[BlackDragon24]

Amazing job as always Dave

It makes one wonder what Intel has up its sleeves for LGA2011. I was planning on waiting an upgrade cycle but sheesh, this is impressive.

Have you had a chance to play with 4GB modules at all?

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Thanks James

The fat modules arrive this week, so I will add something about that if there's anything to add. Failing that, it'll all be in the review of them.

I'm going to build a MATX SB rig in the next few weeks for my workhorse, I'd been waiting to get a full system that run at under 50w idle, and I think I can do it with the H67. Even though there's no overclocking on there, it's going to still be incredibly fast compared to this old laptop I'm using now