Friday, June 28, 2013

Overclocking Sandy & Ivy Bridge In A Nutshell

Good Evening everyone. Welcome to my blog again. I usually try to write on topics from recent technologies , computer stuffs, and electronics circuits and many things. Though thanks to my laziness, haven't written that much! Still I am trying!

Anyway now I am going to write on how to overclock your Sandy bridge & Ivy bridge processors. You will be able to easily overclock your processor after reading this post. But its in brief. If you need to know more about this you can ask me or search on the internet.




Overclocking (OCing) is simply the process of making any computer( this days you can even overclock your smartphone) or it's component run faster than the  specified speed that is told by the manufacturer. For example if you have a processor say a core i5 2500K which has 3.3GHz speed marked. Manufacturer has made this product to run at this speed. But if you supply a bit more voltage(core voltage) or push the multiplier of the CPU it will run faster than 3.3GHz, assume 4.2GHz, so what you have done is OVERCLOCKING. Remember overclocking will produce much heat & consume more power, so make sure you have a good power supply unit & a good cooler.

Why? Why overclocking?
Remember the old movie Back To The Future? Mr. Doc put something in the burner of the train to provide more thermal power to the boiler & eventually achieve higher speed! So, gain from overclocking is Higher Performance! But you may have to sacrifice Lifespan of the component, It will cause higher power consumption & generate more heat.

Is it really necessary?
Technology is running in rocket speed this days! It feels like the first generation Core i7 has just arrived yesterday & now all I can see is the fourth generation Core processors are ready! And so does the softwares & games! Think about Crysis Warhead! Played that when I had just finished my school! & Now its time for Crysis 3 with a recommendation of using a very high end system. What if you can't buy a very high end system? Then you can overclock your relatively cheaper system to get more performance. Though people this days overclock without any reason, but for some people it may be needed.

Now about the processors:

Intel core processors are now on top of the performance chart. They are a bit pricey but ofcourse with good performance. AMD processor are also good. And AMD has sometimes better price vs performance ratio but Intel Core processors are not bad either. Will talk about AMD later, about Intel Core i3 is a real good choice for low budget system, It has two physical cores(so it burns lower electric power) & supports Hyper Threading. Hyper Threading gives this processor a nice boost of performance. But is not a good choice for heavy workload like 3D rendering. Core i5 is kind of all rounder here, good price, has four physical cores & has very nice performance from day-to-day browsing, programming, entertainment, gaming even 3D modeling! The Core i7 is targeted for High end systems. It also has four physical cores(I'm not talking about i7X that has 6 physical cores) but it has Hyper Threading that makes it work like a 8 core processor & give it a nice boost of performance that allows this processor to stay on top of the performance Rank list.

This post is about the core processors of 2nd & 3rd generation. Why 2nd & 3rd generation? Because they are almost identical. Main difference between this two generation is the Lithography 2nd generation core processors use a 32nm lithography where 3rd generation used a 22nm lithography. Using a lower nm results in lower power consumption & higher per watt performance. Processors of this two generations have almost same type of operation. They use a base clock of 100.30MHz & a CPU multiplier. So if the multiplier is set to 31 you will get 31*100.30MHz that is 3109.3MHz or 3.1GHz. That's what is written by the processor manufacturer. One more thing is the temperature. As Overclocking produces more heat you have to dissipate that heat from the CPU. So you will be needing a better cooler. Check the maximum package temperature for this CPU here. What you have to make sure is not to cross this temperature. Important thing here is Core Temperature is different from package temperature. Temperature written here is the Tcase or Temperature of the packaging. If you use Real Temp or software like that, they will show you the core temperature which can be higher than the Package temperature.  

This is the Screenshot of CPU-Z ( You can get it from here or search on the web) from my desktop. As you can see when the CPU is in idle state, in order to consume less energy it clocks itself down to 1.6GHz(first image) & when you put load on it(I used Prime95 to give 100% load on the CPU) it reaches the top level of its marked speed. Here you can see its 3.5GHz. And notice each time the base clock stays at the same only the multiplier has changes. You can change the base clock too. That will also Overclock the CPU but the whole system depends on the base clock. Like the RAM on your system depends on the base clock same as the CPU if you change the base clock value that will ultimately change the RAM speed & which may lead to instability. So, for ease of operation I'm not going to touch the base clock. Now Let's see how to overclock. You have to enter into the BIOS( Basic Input/Output System) of your system. When the system boots up you can hit the proper button (Del for most Asus & Gigabyte boards) to enter there. You can overclock from here. You may also notice the change of core voltage with the frequency. The higher the voltage is the higher the frequency will be.

Tip : Don't try overclocking software as most of them are not stable.

Test Setup 

Processor : Intel Core i7 2600
Cooler : Cooler Master Hyper 412 Slim
Motherboard : Gigabyte GA Z68A-D3H-B3 Rev1.0 BIOS F4
RAM : Transcend 4GB 1333MHz 9-9-9-24 * 4
Hard Drive : Hitachi  1TB SATAII
Western Digital  2TB SATAIII
Power Supply : Corsair CX750


Now after entering the BIOS you may see different thing. I am using the traditional BIOS though Gigabyte has released graphical BIOS for this board but I'm still using the older one. I'm kinda terminal guy! anyway if you are using any other board don't worry you will find the same options their too!

This is how the BIOS looks like.

You can use the keyboard's navigation buttons & enter button to enter into any options. For overclocking we will be needing the first option only. That is the M.I.T. You can also get more information & modifiable setup from other options. A small information is shown in the lower portion of the display that "Change CPU's Clock & Voltage" , that's what you can do from M.I.T. Selecting a different option will show a different information.

After entering the M.I.T you will find this.

Here you can see more options on Modifying frequency & voltage. And most of them are "Advanced Option" so be careful! & Information about the system is shown here too. The BIOS version, The BCLK(the base clock that I was talking about) The CPU frequency, Memory Frequency & Installed Total memory size(RAM) & CPU temperature. As I have already said you have to keep an eye on the temperature. Higher temperature can damage the CPU. Next two options are Core voltage, cores are running on this voltage & DRAM voltage is the voltage RAM is running on.

To check the status of the system you can check the M.I.T. Current status.

Here You can see the Processor Model, Its frequency, DRAM's frequency & Slot information. I am using the first two slots & each one is populated with a 4GB 1333MHz RAM. (Why not higher frequency? Higher frequency RAM on Intel Processor is kind of wastage.Because this processor won't be benefited much from higher frequency RAM. Though 1600MHz would be nice.)

Now the Next thing is Advanced Frequency Settings.

You will be overclocking from here. The first option is the Clock Ratio. It is currently set to 34X. You can change it to over/under clock the CPU. To get the frequency you have to multiply the clock ratio with the BCLK. if you use 42X then you will be getting 42*100MHz that is 4200MHz/4.2GHz.

You will see this after clicking the CPU Clock Ratio. Here the maximum value is 42 because I'm using a non-K version processor here. You can use a K processor such as a i7 2600K to get unlocked Multiplier. That will allow you to overclock even more. Overclocking CPU will give more pressure on the motherboard's power phase(it supplies power to the processor iGPU RAM). You will need a good motherboard for stable overclocking.

You can also look for Advanced CPU core feature , You can enable BCLK control that will allow you to change the BCLK. But as I have said earlier that may cause stability problem & you can only OC to smaller margin with BCLK. You can change the Memory Multiplier. That's also same as the CPU. Currently it is at 13.33 that will result in 13.33*100MHz=1333MHz. You can just left it to Auto. If you find that it is not working at the rated manufacturer speed you can change it. The Next thing is the iGPU clock. You can Overclock your integrated GPU too. Core series comes with integrated Graphics chip that is located inside of the processor. You can overclock that too. But you will be needing supported motherboard for doing that. 

Next stop the advanced options. 

You can also change the Ratio from here. Both will result in the same. If you want to overclock really high you have to enable the CPU PLL over voltage. For 4.2GHz or something you can keep it at disabled. 

If you overclock better to disable the Turbo Boost! (What turbo boost do is, when system is loading on a single core turbo boost automatically disable one or more core to achieve higher core frequency of the running core. Same as the AMD's Turbo core. If you overclock you won't be needing this.) Turbo Ratio wont be needed If you OC so just leave them. You can enable or disable cores or Hyper Threading. If You are planning on a quick overclocking just leave them as they are. You can set a bit higher value for core current limit though. Like 100Amps.

This is how it will look like after selecting higher Ratio. As you can see it is showing that it will reach 4.2GHz.

This is the system Memory Multiplier. Talked about it earlier. Leave it to auto. It's fine.

 You can also overclock the iGPU. Not a good idea because it doesn't result in any major difference. 

This is the advanced memory settings. You can change the memory multiplier from here too.

Just leave them as they are.

This is the Motherboard voltage Control. From here you can control any voltage. But be careful when changing voltages. You can adjust voltage drop using the option LLC(Load Line Calibration). LLC prevents the voltage from dropping but for very short amount of time it may push the voltage over the limit. So better to follow Intel Spec. I will write about LLC later. Higher level of overclocking may require LLC though.

Okay Now after overclocking (40X multiplier) I have turned on the system again. Look at the frequency now.

Also notice that the temperature has gone 4 degree higher than earlier & core voltage has also gone higher. Remember Maximum Core voltage for 24/7 usage of Sandy Bridge is 1.375V & Ivy bridge is 1.28V. Don't push too much. You are overclocking for your own use. Not for a world record.

You can also see more settings from Misc Settings. Like enabling Virtualization(If your CPU is supported).

That's how it is. You can easily overclock by doing this. I have tested system stability with Intel Burn Test & Prime95. It was good. No problem at all. You can also do it if you want.


If you plan on overclocking get a K series processor. Like i5 2500K/i7 2600K/ i5 3570K/ i7 3770k.

Use a better processor cooler with it. Overclocked processor will produce a lot of heat, you have to dissipate it in order to stay stable. You can use Real Temp to see the core temperature.

You will need chip set (or motherboard whatever you say) to overclock. Not all boards come with overclocking feature & good power phase. So if you want to overclock 2nd or 3rd generation processor buy Z68/Z77 board. 

Last but not the least make sure you know what exactly you are doing.

What will you get?

You will get better performance from the same machine. If you render models with 3DS max, you can render faster with an overclocked processor.

That's all. Good luck everyone. And don't forget to check back for more.


  1. Did u OC it only for test, or do u regularly use it at 4GHz? I m curious to know about the stability of this non K processor

    1. sorry for being late.
      I'm running it at 4GHz for 24/7.
      I just changed the power supply unit to a Corsair CX750.
      and not a single problem so far. no hang, no blue screen.