You overclock your system at your own risk. Overclocking your CPU could cause the CPU to fail, or reduce its useful life. Neither MyCE.com nor myself will take any responsibility for any damage that may be caused to your CPU or system by following this guide.
Easy overclocking guide for Intel Sandy Bridge and Ivy Bridge CPUs.
If you are an extreme overclocker then this guide is probably not for you. What I intend to cover in this guide is a sensible CPU overclock that can be used 24/7, and all without power consumption going through the roof.
There are many ways to overclock these CPUs and I'm not going to claim that this way is the best way, but simply that it should work for 95% of the people who would like to get some extra grunt from their CPU without the need for extreme cooling solutions, or having to worry about power consumption getting out of hand.
First of all. let's cover what you will need to successfully overclock a Sandy Bridge or Ivy Bridge CPU.
The first thing of course is a CPU with an unlocked multiplier. For Sandy Bridge and Ivy Bridge that would be a CPU model with a "K" at the end. 2600K for example for Sandy Bridge, and 3770K for example, for Ivy Bridge. Overclocking these CPUs is simply a matter of stepping up the multiplier. Of course it isn't quite that simple, as you will need to watch how much voltage you push through these CPUs, and also that stepping up the voltage and clock speed will inevitably produce more heat.
The next thing you will need is a chipset that allows the CPU to be overclocked. For this we will only cover the most popular mainstream chipsets.
See the table below.
A third party cooling solution.
If we are going to look at overclocking seriously then the first thing you will require is a third party cooling solution. The stock cooler is really only effective at clock speeds up to about 4GHz. To go faster than this then a third party cooling solution is required. Don't worry, for this guide a good quality air cooling solution is all that's required.
Although Sandy Bridge and Ivy Bridge both share the same CPU architecture, there cooling requirements are quite different. Sandy Bridge is a 32nm part, while Ivy Bridge is a 22nm part. Also, the CPUs internal thermal interface are very different. Sandy Bridge uses a soldered integrated heat spreader which is soldered directly onto the CPU die, while the Ivy Bridge integrated heat spreader uses a TIM (thermal interface material) to make contact with the CPU die.
Solder is much more effective at transferring heat when compared to a thermal paste.
If we look at the above picture of an Ivy Bridge CPU, the metal part covering most of the CPU package is the integrated heat spreader. The heat spreader serves two purposes.
- It protects the CPU die.
- It spreads the heat produced by the CPU die onto a larger surface area, which also acts as the interface between the CPU and the cooling solution.
Let's get something straight right from the start. Despite what you may have heard, Ivy Bridge produces less heat than Sandy Bridge. The problem with Ivy Bridge is twofold. First you have a smaller CPU die, so there is less surface area to make contact with the integrated heat spreader, and Intel use a thermal paste to thermally transfer the heat from the CPU die to the integrated heat spreader. So although Ivy Bridge produces less heat, it struggles to get that heat from the CPU die to the integrated heat spreader. Once the heat is transferred to the heat spreader, it's very easy to get rid of that heat. So a good air cooling solution will do the job every bit as good as an expensive water cooling solution.
Measuring how hot the CPU is getting.
The best way to measure the CPU temperature is to measure the heat of the CPU cores themselves, and lucky for us, there is a couple of excellent free applications for doing this.
The maximum core temperatures are as follows.
- Sandy Bridge TJmax is 99c
- Ivy Bridge TJMax is 105c
If TJmax is reached then the CPU will throttle back to prevent permanent damage to the CPU die, but you don't want to get to close to those temperatures. For Sandy Bridge, 75C really shouldn't be exceeded for any prolonged period. For Ivy Bridge, 85C should not be exceeded for a prolonged period.
Measuring vcore voltage.
This is the amount of voltage that is being supplied to the CPU cores.
You will no doubt have seen on some overclocking sites, that people are pushing crazy amounts of voltage through the CPU cores, in order to get that last 100MHz of speed. For this guide we will be a bit more conservative and sensible.
The maximum safe voltages for 24/7 use are as follows.
- Sandy Bridge 1.375 volts
- Ivy Bridge 1.28 volts
Measuring the core voltages is again very easy, and free. CPUZ
is probably the best option for this.
Overclocking the CPU.
To actually overclock the CPU, we are going to do this through the UEFI (BIOS). The method I will use is the same for Sandy Bridge and Ivy Bridge, and as I said at the top of the page, we are going to do this without sending power consumption through the roof.
First of all you will need to enter the UEFI (advanced settings), and you will need to consult your motherboard manual as to how you enter the UEFI (advanced settings). I will use an Asus Z77 motherboard for this task, but the same settings that I use should be a available for most Sandy Bridge and Ivy Bridge compatible motherboards.
Once you have reached the advanced settings page, you should then look for the overclocking section.
So, below are the settings you will need to change.
- Overclock tuner - Manual
- BCLK Frequency - 100.0 (This locks the base clock to 100MHz, and locks down the PCIe bus to 100MHz. This is very important)
- Turbo ratio - Manual
- Ratio sync control - Enabled (This adjusts all the CPU cores to the same multiplier)
Almost all Sandy Bridge and Ivy Bridge CPUs should be able to reach 4.4GHz with ease with a good air cooling solution, but let's start at a lower multiplier. We'll start at 4.1GHz, then work our way up a notch or two.
Adjusting the core voltages.
The next setting is how to control the core voltage. Many overclockers are stuck in the old ways of how to get a stable overclock, by setting a fixed core voltage. Unfortunately this method is old, produces extra heat, and wastes energy, and doesn't really apply to Sandy Bridge and Ivy Bridge. To overclock Sandy Bridge and Ivy Bridge we will use a voltage offset. This method is much more energy efficient and flexible. It will inject more vcore when it is required (under load), and then lower vcore when the system is on low load or idle.
The required settings are as follows.
- CPU voltage - Offset mode (change from auto to offset)
- Offset mode - + (plus) This will increase the vcore by an offset amount
- CPU offset voltage - 0.050V (be careful when setting this).
You will notice that my setting is 0.025V, but we will start slightly higher, then after some stability testing you can reduce this to a value that suits your system. The lower you can set the "offset" voltage the better, as a lower offset voltage will result in less heat being produced. However, the priority must be stability. Have patience with this setting, it is well worth the effort.
To test for stability you will need some way of loading the system. I would not recommend running any torture type test for any length of time, they can degrade the CPU if you push them too far. I have found that running the (free) benchmark application CineBench (single run on the Multi thread CPU test) will be fine for a quick test. If it completes the test, you can be fairly sure that your overclock is stable.
You will also need to test for stability when the system is idle, as the power saving characteristics of these CPUs can mean that the system will be stable while loaded, but unstable when at idle or low load.
If the overclock is stable then you may like to try and go for a higher multiplier. Take this one step at a time, and test for stability at each increase of the CPU multiplier, and keep an eye on vcore and temperatures as you go.
Energy efficient overclocking.
The enthusiast overclocker will generally switch off all the power saving modes of the CPU, and lock the CPU frequency at their max overclock speed. This was always the case with the older generations of Intel CPUs such as Pentium, Core, and Nehalem. Sandy Bridge and Ivy Bridge are very different animals. Their frequency ramping performance is much improved over those older generations of CPU's, and reach idle speed 1600MHz to max overclock frequency in a fraction of a second. So for Sandy Bridge and Ivy Bridge, the CPU power saving modes should be left enabled.
This has two very attractive benefits.
- You save a lot of energy
- You produce a lot less heat.
Being realistic, you don't require a CPU clocked at 4.4GHz to browse the Internet, or type a document in Word. So leaving the power saving settings enabled will allow the CPU to throttle back when load isn't high, then ramp up the CPU frequency to max when you do require a lot of CPU grunt. For example, while re-encoding a video stream.
To change the CPU power management settings, you will need to go to the "advanced page" and then select "CPU advanced settings" and then "CPU power management".
From here you would make the following changes.
- Enhanced Intel Speedstep Technology (EIST) and set it to enabled. This will allow the CPU to seamlessly step from 1600MHz all the way up to your max overclock frequency.
- Turbo mode - enabled
- CPU 1E - enabled (allows the first power saving CPU state)
- CPU C3 and C6 Report - enabled. This will allow the OS to send power requirements back to the motherboards power management processors.
- Package C state support - enabled. This enables C3 and C6 support at the hardware level.
Overclocking the integrated graphics processor
Both the Sandy Bridge and Ivy Bridge processors have an integrated graphics processor (iGPU). On Sandy Bridge you will either have HD2000 or HD3000. On Ivy Bridge the iGPU is designated HD2500 and HD4000.
All these parts can be overclocked, unless you happen to be running a motherboard with the P67 chipset. So what is the benefit of overclocking the iGPU?
Well to start with, 3D performance in games will see a benefit, but it's not only games that will see a boost in performance, Intel Quick Sync will also see a performance boost. So let's take a look at overclocking the iGPU.
Just like overclocking the processor itself, in this guide I will stick to a sensible overclock that most people will be able to achieve very easily, and also without sending temperatures and power consumption sky high.
How to overclock the iGPU
You will first need to enter the system UEFI, and then enter the system overclocking screen.
Next find the iGPU max frequency setting, and choose your max overclock frequency. I have found that the following is very stable.
- Sandy Bridge HD3000 - 1600MHz
- Ivy Bridge HD4000 - 1500MHz
Although Ivy Bridge is running at a lower frequency, it will still easily outperform the Sandy Bridge iGPU. Once you have set the max iGPU frequency you can then move onto setting the iGPU voltage. Because we are overclocking the iGPU it will inevitably require a slightly higher iGPU core voltage.
Once again we will use the "offset" method for controlling the iGPU core voltage, so we will first set the option to "offset mode". For the offset voltage, I have found that setting it at "auto" is the most stable, and produces very little extra heat.
To finish this guide.
If you can get all the settings above to work in a stable manner, then not only will you have a nice and sensible overclock and a faster system, but also you will be doing so without producing vast amounts of heat, and without sending power consumption through the roof.
I will only add, be careful, and watch the core voltages do not get to high, and watch those temperatures.