Core i7 Overclocking Guide For Beginners

[Clunk]

Core i7 Overclocking Guide For Beginners.



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Index.

1. Index, Intro, Jargon Explained And Theory.
2. Getting Started And Overclocking to 3360MHz (3.36GHz).
3. The Next Step - 3801MHz (3.8GHz).
4. The 4000MHz (4GHz) Milestone.
5. Troubleshooting.
6. Memory Overclocking - To Follow.

It's that time again folks! In our ever popular series of overclocking guides, we've covered most of the Intel chipsets from the launch of Core 2 Duo. Overclocking the C2D platform was really easy once you got to know what everything did, i7 is no exception, and in many ways, the basics are the same, however, there are a few new things to get to grips with, and that's exactly what we're going to do in this guide.

The i7 platform has been around for a few months now and has become quite popular, especially in enthusiast circles. I've tried out many motherboards from different manufacturers and my favourite, bar none is the Asus P6T Deluxe OC palm (Just P6T from here on in). I will be using the P6T in the guide and I will be referencing its BIOS settings throughout - I'll also be using an Intel i7 920 DO processor and some Corsair Dominator 1600MHz memory, a triple channel, 6GB kit to be exact, more on the hardware side of things later.

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 i7 920 from its standard 2.66GHz speed and run it as fast as it'll go with 1.25v 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.

Why 1.25v Vcore?

The i7 processors run hot when you start to add extra voltage, 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.

We already know that your i7 processor runs hot, so you will need a decent 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 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 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. At the moment, Corsair are doing some excellent PSUs, and you can't really go to far wrong with any of their range.

Why do we need a good power supply?

You need a good PSU because it is the heart of your system. When you start to 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.

When choosing your memory with a view to overclocking, it's a good idea to get a set of modules that will go slightly higher than you plan to go (headroom). Give yourself a bit of headroom by getting some decent quality memory, it will be one less thing to worry about later if things don't quite go as smoothly as you'd planned. For overclocking on the i7 platform, I'd recommend at least 1600MHz memory and if you are using Vista, then a 6GB kit will keep your system happy too.

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

Start with a stable system.

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 the for stress testing only.
• CoreTemp - This gives us a relatively accurate temperature reading for our CPU's cores.

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 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 might 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 i7 overclocking.

Basically, all we are doing is running the CPU faster than it was intended, we do this by raising the BCLK (Base Clock) and adding a little voltage, it's as simple as that.

What CPU should I get?

Unlike the huge C2D range, the i7 range is quite small, with only four models currently on the shelves, the 920, 940, 950 and 975, the 920 comes in at just over £200 and represents the greatest bang for buck. Considering that when overclocked, pretty much all the models perform the same, a 920 is a no-brainer at the moment.

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) - To keep things as simple as possible, this is the setting that we will be increasing to achieve our desired overclock. The default value for our 920 processor is 133.
• QPI (Quick Path Interconnect) - The QPI connects the processor to the In Out Hub (IOH) - In other words, it is the way that your processor talks to the rest of your system.
• Multipliers (Multis) and Dividers - As with previous platforms, i7 uses multipliers and dividers, but the way that i7 differs is that there are several of them for various things. For example, your CPU has a default multiplier (Multi) of 21x and there is a multiplier for the memory and the UnCore (We don't need to be concerned with these at the moment as this is a beginner's guide).
• UnCore - This is simply any part of the processor that is not the core, such as the memory controller or cache - It isn't too relevant for this guide, but I do mention it, so it is better explained.
• Turbo Mode - See the explanation below**.
• Vcore - This is just another term for the main CPU Voltage.

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. If there are any other settings you'd like me to add, just give me a shout.

Item	Asus	DFI	Gigabyte	Foxconn	EVGA
Main CPU Voltage	CPU Voltage	CPU VID Control	CPU Vcore	CPU Core Voltage	CPU Vcore
Memory Controller Voltage	QPI/DRAM Core Voltage	CPU VTT Voltage	CPU VID Control	CPU VTT (Uncore) Voltage	CPU VTT Voltage
Main Memory Voltage	DRAM Bus Voltage	DRAM Bus Voltage	DRAM Voltage	DRAM Voltage	DIMM Voltage
VDroop Control	Load-Line Calibration	VCore Droop Control	Load-Line Calibration	CPU VDroop Compensation	EVGA VDroop Control

Calculating Your Processor Speed.

To try and simplify things further, let's take a look at how we work out our processor speed and how it related to the multipliers and dividers.

The bottom line is that the CPU Multi x BCLK = Processor speed in MHz, so at the stock BCLK of 133 and the 21x multi, we get 2793MHz. The astute among you may have noticed that this is slightly more than the the 2660MHz (2.66GHz) that is quoted on the CPU box and the reason for this is Turbo mode.

**Turbo mode is quite a complex feature, but to sum it up, if enabled, it will give you an extra multi, so on our 920, we get 21x instead of 20x - If you do the maths, Turbo off = 20x 133 = 2660MHz (2.66GHz). For the purposes of this guide, we will be leaving Turbo mode on.

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...

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 for details), 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 3360MHz (3.36GHz).

Entering the P6T's BIOS, we need to head for the "Extreme Tweaker" section. Firstly, we neeed to set the BCLK to 160, this will give us 3360MHz (3.36GHz). The rest of the settings are as follows:

The Ai Tweaker screen is quite a long one, so I've split it into three screen shots.

First up, make sure everything looks like this:

Ai Overclock Tuner - Manual
CPU Ratio Setting - Auto
Intel (R) SpeedStep (TM) Tech - Enabled
Intel (R) Turbo Mode Tech - Enabled
BCLK Frequency - 160
PCIE Fequency - 100
DRAM Frequency - DDR3 - 1282MHz - If you use memory that is slower than 1600MHz, you can use the next lowest setting here, however, if you use faster memory, such as 1866MHz or even 2000MHz, please stick with this setting for now.



Next, the DRAM Timings.

You only need to change the top Four 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 further down for that:



DRAM CAS# Latency - 8 DRAM Clock
DRAM RAS# to CAS# Delay - 8 DRAM Clock
DRAM RAS# PRE Time - 8 DRAM Clock
DRAM RAS# ACT Time - 24 DRAM Clock

Again, this is a long screen, so I've split it into two.

DRAM Timings - Top.



DRAM Timings - Bottom.



Back to the Ai Tweaker - Middle.

Here we can see that the DRAM Bus voltage is at 1.66v - This is your main memory voltage setting, Asus X58 boards tend to go from 1.64v to 1.66v, missing out the 1.65v that our modules are rated at, and that Intel recommend to be the maximum on the i7 platform. If your memory is rated for 1.65v (which many triple channel kits are) try and stick at 1.64v or 1.66v to be safe, it's really easy to damage memory modules by over-volting them and in a new twist the CPU can be damaged by overvolting the memory too, so don't be tempted to go higher, of course, if your memory uses 1.6v or less, then you don't need to worry about this!

CPU Voltage 1.10000v
CPU PLL Voltage - Auto
QPI/DRAM Voltage - Auto
IOH Voltage - Auto
IOH PCIE Voltage - Auto
ICH Voltage - Auto
ICH Voltage - Auto

DRAM Bus Voltage - 1.66v
DRAM DATA REF Voltage on CHA - Auto
DRAM CTRL REF Voltage on CHA - Auto
DRAM DATA REF Voltage on CHB - Auto
DRAM CTRL REF Voltage on CHB - Auto
DRAM DATA REF Voltage on CHC - Auto
DRAM CTRL REF Voltage on CHC - Auto



Moving to the lower part of the Ai Tweaker, there's not much to set here, apart from enabling Load-Line Calibration.

Load-Line Calibration - Enabled
CPU Differential Amplitude - Auto
CPU Clock Skew - Auto
CPU Spread Spectrum - Auto
IOH Clock Skew - Auto
PCIE Spread Spectrum - Auto



Once that's all done, save and exit and boot to windows, if you did everything correctly and it doesn't boot properly, then you need to check out the troubleshooting 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 1920MHz (1.92GHz), this is because of Speedstep - It is one of Intel's power saving features and it just lowers the Multiplier and voltage 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. You can actually see this in action by dragging the CPU-Z screen around the desktop, the CPU speed will increase and then decrease as you let go.

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 640MHz, 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 it 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. Many people still use OCCT, however, even the newest versions do not fully stress all of the eight threads available.

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 screenshot below and then click ok to start the test.



Now is a good time to open CoreTemp too. If you arrange Prime, CPU-Z and CoreTemp on your desktop, it should look something like this - You can see that the CPU speed has jumped to 3360MHz 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 60c-65c.

Another thing worth mentioning (although not directly relevant to this guide) is that Prime95 is running eight threads - What does this mean for you? Each i7 processor has four cores, but they also have Hyperthreading, which means that your operating system sees each physical processor (core) as two virtual processors (cores). This has benefits and drawbacks, if you have software that can deal with eight processors and use them correctly, then Hyperthreading can boost performance significantly, however, the performance comes at a price, the price is heat! For our tests, the heat generated is fine as it will give us a good measure of how efficiently our cooling is working.



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.

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, 3801MHz (3.8GHz)...

[Clunk]

Overclocking To 3801MHz (3.8GHz) @ 1.2v.

Remember how we worked out our processor speed? Using that same calculation, we will need to be going for a BCLK of 181. So, 181 x 21 = 3801MHz. Easy!

The drill is the same as before, back to the BIOS and we need to set the BCLK to 181 first. We will also need to increase the Vcore (CPU Voltage) to match our overclock, so let's go for 1.2v to begin with.

Ai Overclock Tuner - Manual
CPU Ratio Setting - Auto
Intel (R) SpeedStep (TM) Tech - Enabled
Intel (R) Turbo Mode Tech - Enabled
BCLK Frequency - 181
PCIE Fequency - 100
DRAM Frequency - DDR3 - 1451MHz - If you use memory that is slower than 1600MHz, you can use the next lowest setting here, however, if you use faster memory, such as 1866MHz or even 2000MHz, please stick with this setting for now.



DRAM CAS# Latency - 8 DRAM Clock
DRAM RAS# to CAS# Delay - 8 DRAM Clock
DRAM RAS# PRE Time - 8 DRAM Clock
DRAM RAS# ACT Time - 24 DRAM Clock

CPU Voltage 1.20000v
CPU PLL Voltage - Auto
QPI/DRAM Voltage - Auto
IOH Voltage - Auto
IOH PCIE Voltage - Auto
ICH Voltage - Auto
ICH Voltage - Auto

DRAM Bus Voltage - 1.66v
DRAM DATA REF Voltage on CHA - Auto
DRAM CTRL REF Voltage on CHA - Auto
DRAM DATA REF Voltage on CHB - Auto
DRAM CTRL REF Voltage on CHB - Auto
DRAM DATA REF Voltage on CHC - Auto
DRAM CTRL REF Voltage on CHC - Auto

Load-Line Calibration - Enabled
CPU Differential Amplitude - Auto
CPU Clock Skew - Auto
CPU Spread Spectrum - Auto
IOH Clock Skew - Auto
PCIE Spread Spectrum - Auto

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 congratulations, you have just achieved an 1141MHz overclock!



At the beginning of the guide, I said that we'd go as high as possible with 1.25v, so that's exactly what we are going to do next.

[Clunk]

Overclocking to 4000MHz (4GHz) @ 1.25v.

How does 4GHz sound? Daunting? Well it needn't be, and here's how to get there. It couldn't be easier really. One thing to keep in mind is that as you go higher, the temps are going to increase and depending on what type of cooling you have, this could be where you have to call it a day. On the other hand, if you have really good cooling, you could still have a way to go. As a personal preference, I'd rather not see the temps hitting much over 75c, in the screen shot below, you can see that my temps were nudging 78c in paces and this was just about OK as it wasn't a steady 78c, just the occasional peak.

Ai Overclock Tuner - Manual
CPU Ratio Setting - Auto
Intel (R) SpeedStep (TM) Tech - Enabled
Intel (R) Turbo Mode Tech - Enabled
BCLK Frequency - 190
PCIE Fequency - 100
DRAM Frequency - DDR3 - 1523MHz - If you use memory that is slower than 1600MHz, you can use the next lowest setting here, however, if you use faster memory, such as 1866MHz or even 2000MHz, please stick with this setting for now.



DRAM CAS# Latency - 8 DRAM Clock
DRAM RAS# to CAS# Delay - 8 DRAM Clock
DRAM RAS# PRE Time - 8 DRAM Clock
DRAM RAS# ACT Time - 24 DRAM Clock

CPU Voltage 1.25000v - This is our maximum Vcore
CPU PLL Voltage - Auto
QPI/DRAM Core Voltage - 1.3v - We need to up this to 1.3v to maintain stability, or at least I did on my CPU, your mileage may vary and you may need slightly more or slightly less.
IOH Voltage - Auto
IOH PCIE Voltage - Auto
ICH Voltage - Auto
ICH Voltage - Auto

DRAM Bus Voltage - 1.66v
DRAM DATA REF Voltage on CHA - Auto
DRAM CTRL REF Voltage on CHA - Auto
DRAM DATA REF Voltage on CHB - Auto
DRAM CTRL REF Voltage on CHB - Auto
DRAM DATA REF Voltage on CHC - Auto
DRAM CTRL REF Voltage on CHC - Auto

Load-Line Calibration - Enabled
CPU Differential Amplitude - Auto
CPU Clock Skew - Auto
CPU Spread Spectrum - Auto
IOH Clock Skew - Auto
PCIE Spread Spectrum - Auto





So there we have it, some basic overclocking on the i7 platform. Next up, we will have a look at the memory and how we can make it run faster.

[Clunk]

i7 Overclocking Guide For Beginners - Troubleshooting.

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 P6T 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 your PC is struggling at moderately low overclocks, make sure that you definitely have the RAM set so that it isn't running above what it is rated at. Obviously this will cause problems, as, when you start to up the BCLK, the RAM speed will also increase and immediately, you will be running the RAM faster than it should go, resulting in an unstable system. If in doubt, set the CPU to 133 and the RAM to 1066MHz and take it from there.

• 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 17x in CPU-Z, when it should be higher (21x 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 - Every X58 board that I've tested has had 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.

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.

[Clunk]

Updated, more to follow

Please DIGG

[DaddyCool]

Thank You So Much. i think i run into my first problem i cant lower my CPU voltage below 1.25000. i tried - and direct keys but to no avail. also its in yellow font. Im using P6T MBoard. any ideas on this? is there a jumper i have to set? i can change everything except CPU Voltage.

[Clunk]

You should be able to set it to whatever you need to. Just highlight the "Auto" and then type in 1.1 (or whatever) and hit enter.

If it still persists, try resetting the CMOS, it could be something as simple as that

[DaddyCool]

Originally Posted by Clunk

You should be able to set it to whatever you need to. Just highlight the "Auto" and then type in 1.1 (or whatever) and hit enter.

If it still persists, try resetting the CMOS, it could be something as simple as that

I tried everything now.

everytime i input something lower than 1.25 is set to 1.25 but more than that its ok, - & + sign when press will give me lowest value 1.25 next is auto.

i tried unplugging and resetting CMOS but still the same.

i tried removing the batt then reset CMOS still to no avail.

Except for CPU voltage all the settings goes to min. to max. settings with no problem.

Anything else i can try?

[Clunk]

That's a strange one.

Have you ever updated the BIOS? Sounds like you could do with installing the latest one