BEST Intel Overclocking Tutorial

This is my intel overclocking guide version 1 for you. It's mainly for core2duo and quad processors.


First of all, you need the following programs :

CPUz:
Displays your current vcore, FSB, multiplier, RAM settings. You'll need it all the time. 
RealTemp:
Displays the temperatures of the cores. Must have.
OCCT:
Used to check stability of the system.
Prime95:
Used to check stability of the system. Use this for 12h or OCCT for 2h.
Intel Burn Test:
Not for beginners. This program WILL stress the CPU, Memory, North Bridge, and other system components to their highest extent! Make sure your PC is properly cooled and ventilated! I prefer the beginners to use it after their system passes OCCT or prime95 test.

What is overclocking?

Overclocking is the process of making your hardware run faster then originally intended by the manufacturer. It is operating hardware (particularly CPU, RAM, motherboard, and video card) above the specs to which a piece of hardware is expected to, has been tested to, and is warranted to perform. 

Overclocking is more of an art than a science. There is no combination of settings that will yield the best results for every system. it is and will be a trial and error process. Don't be afraid to experiment, but I suggest to always go slow. Experience can make overclocking easier.


What is FSB?

FSB is Front Side Bus also known as System BUS and connects the CPU with the main memory and is used to connect to other components within the computer. Depending on different processors, the FSB can range from 66MHz to 500MHZ and beyond. That means Rated FSB the quad pumped processors will range from 476MHz to 2000MHz and above.

Remember, throughout this tutorial and throughout all the tuts and overclocking discussions, try to think about external clock speed as FSB. Because, the latest processors are quad pumped. That means, the Rated FSB of these processors are 4 times the original FSB [I mean the external clock speed, that how intel owners name the original FSB]. Suppose, I say that the FSB is 333MHz, then the Rated FSB is 333MHz*4=1333MHz. But you don't need to worry about the rated FSB. All you need to know about the "FSB". Because the BIOS will allow you to edit the FSB, not the rated FSB. 

Rated FSB = FSB*4 

Overclocking in the BIOS:
Many boards will offer you overclocking softwares. But the best way to overclock is to use the BIOS.

Limitations:

Each hardware component has physical limitations that, at a minimum, meet the stock specs. In the process of overclocking your system, you'll face motherboard limit, processor limit, ram limit. PSU and cooling of your system will also affect the overclocking process.

Basics:

First of all, read your motherboard manual properly. Make sure that you know everything about your BIOS settings and know how to reset your BIOS if your PC just keeps restarting or acts abnormally or doesn't reboot normally. 

Now, the formula is-

Code:

CPU Speed = CPU Multiplier x Front Side Bus [FSB]

For example, the default speed of E7200 is 2.53GHz. 
Here, default FSB is 266 MHz and default multiplier is 9.5.

SO, [266MHz*9.5]= 2530MHz=2.53GHz

Some of the processors have locked multipliers. That means you cannot increase or decrease the multipliers. In some case, you can only decrease the multiplier. And in some processors, they give you the ability to both increase and decrease the multipliers.


Memory Bandwidth:

DDR = Dual Data Rate. If your use DDR,DDR2,DDR3 RAM, your BIOS may list RAM/DRAM frequency (Half of RAM's rated DDR speed) or actual DDR speed. The PC equivalent is 8 times the DDR speed or 16 times the actual frequency. As example we can say DDR400 is rated as PC3200 (also DDR2-400 = PC2-3200). DDR2-800, is DDR2 memory rated at 800Mhz. However, that is its rated (Dual Data Rate) speed. The memory is actually only running at 400Mhz, but since data is being read on both peaks of each cycle, its rated speed is doubled.
People compare the speed of the memory as a ratio to the CPU's FSB. 


What is Divider?

The ratio of CPU:RAM is known as a divider. For this ratio, you use the actual memory speed, not the rated speed.

For example, a CPU with a FSB of 266.66MHz will be in a 1:1 ratio with memory at 266.66Mhz [DDR2-533]. Or a CPU of 400MHz will be in 1:1 ratio with a memory at 400MHz [DDR2-800]. Depending on motherboards, you will see 1:1, 2:3, 3:4, 4:5 etc ratios. Cheap motherboards will not give many ratios. Some boards give this ratios as numbers like 2x, 2.5x, 3x etc. In those cases, just multiply the numbers with the FSB to get the cpu speed.

Code:

The max FSB supported by a  DDR-xxx ram is xxx/1=yyy
The max FSB supported by a DDR2-xxx ram is xxx/2=yyy.
The max FSB supported by a DDR3-xxx ram is xxx/4=yyy.

Like DDR2-800 rams can support a maximum of 400 FSB if the ram is not overclocked.



BIOS Settings:

All the BIOS are not same. Some features are named differently on different motherboards. Some are not available and some are hidden. You're on your own to figure them out and that shouldn't be that tough. It goes without saying that your board will have these organized differently as well. Because you can't rule out the basic settings from the BIOS. xD

Enter the BIOS and look for the following options. The BIOS on most boards can be accessed by pressing the DEL key at system startup. Browse through the BIOS options and get familiar. Try to know if your mobo has hidden options. If any, learn which button will unlock them. Generally Ctrl+F1 works. Or there should be an option saying "Enter advanced options" or something like that.


Now we will fix some basic settings. [Not overclocking, but are needed to overclock]

First Disable this settings-

C1E, Max CPUID value limit , Vanderpool, SpeedStep/EIST, Legacy USB, Spread Spectrum.

C1E and Speedstep/EIST are power saving options. You can turn them on later and see that if the overclock stays stable.

Then Enable these settings-

CPU TM function/TM2 function, EDB/ Execute disable bit, PECI.


Now, you'll have to set any options relating cpu frequency and ram frequency to manual. But, for first time set the voltage and ram timings options to auto. Also, if there's any "AI' option, set it to manual.


Ok, now we will overclock. In my case I'll overclock a E7200 which has a default FSB of 266. 

PCI Express Frequency – Set this to 100 MHz first. Don't use auto.

PCI Clock Synchronization - Use 33.33 MHz here. Don't use auto.

DRAM Frequency - This the speed your RAM will run. This will change with the cpu FSB. Make sure you don’t exceed the amount for which your specific RAM is rated. Most good boards will offer several fsb : dram dividers. Some will offer a few. 

Assuming that you’re using a 320 MHz FSB the ratios will be:

Code:

1. FSB :  DRAM
   2. 1:1 =  320 MHz : 640 MHz
   3. 4:5 =  320 MHz : 800 MHz
   4. 2:3 =  320 MHz : 960 MHz
   5. 5:8 =  320 MHz : 1024 MHz
   6. 3:5 =  320 MHz : 1066 MHz
   7. 1:2 =  320 MHz : 1280 MHz

If you use 333 MHz FSB, ratios will be-

Code:

1. FSB :  DRAM
   2. 1:1 =  333 MHz : 667 MHz
   3. 4:5 =  333 MHz : 833 MHz
   4. 2:3 =  333 MHz : 1000 MHz
   5. 5:8 =  333 MHz : 1066 MHz
   6. 3:5 =  333 MHz : 1111 MHz
   7. 1:2 =  333 MHz : 1333 MHz

If you use 400 MHz FSB, the ratios will be-

Code:

1. FSB :  DRAM
   2. 1:1 = 400 MHz : 800 MHz
   3. 4:5 = 400 MHz : 1000 MHz
   4. 2:3 = 400 MHz : 1200 MHz
   5. 5:8 = 400 MHz : 1280 MHz
   6. 3:5 = 400 MHz : 1333 MHz
   7. 1:2 = 400 MHz : 1600 MHz

You can calculate these yourself with this formula:

Code:

DRAM Final Clockrate = [2 x FSB]/Divider

Example, 4/5 divider @ 400 MHz FSB: (2 x 400 MHz)/(4/5) = 1,000 MHz.

If your ram is only 800 MHz, you have to select FSB as 267. Then you will be using your maximum ram without overclocking the ram. Or you have to select different ratio. 

Now, set ram timings and ram voltages to auto because we are not overclocking the ram yet. And as you are new, do ot mess with nortbridge voltage.

Now, I want you to see your default cpu voltage or cpu vcore [It is supposed to set to auto, the voltage will be shown]. Write it down and set cpu voltage or cpu vcore to manual. And put the value that you just wrote manually. Suppose, when your cpu vcore was set to auto, its value was 1.175. Now set it to manual and manually put the value 1.175. This will ensure safety. Now save the settings[Save to a profile if available].

[Step XXX]
Now, increase your FSB by a small amount like 5-10MHz and make sure the ram is not overclocked [Ram can be underclocked]. Then save and restart your PC. If you can boot normally, go to step xxx. Raise your FSB upto to the amount you want[by small increment and saving and restarting- be sure not to get a very high frequency. If you browse the net, you will see what is safe overclocked FSB and voltage for your processor ] until the system resets automatically or if you cannot boot. Ok, now get to BIOS and increase your vcore a bit[1 step] and see if you can reboot[Never go over 1.25v because you are new. Veterans run PCs at even 1.45-1.5 volts]. If you cannot reboot properly, increase the voltage a notch. Increase it notch by notch until you can reboot properly[Don't go over 1.25v]. If you can reboot properly, run OCCT cpu test for 2h for stability check. If you fail, lower the FSB until you are stable with OCCT. If you pass, run 5 cycles of intel burn test. If you pass, note the highest temperature on load and while idle from real temp. Also note the voltage while idle and voltage on load from CPUz. If you think the temperatures are too high[more than 55 degree Celsius on load], decrease the vcore a notch. If you cannot reboot successfully, lower the FSB until it is stable with OCCT. 

You don't want to overclock more than 20% if you are new. So be happy with mild overclocking unless you gain experience. 

Generally, you won't be able to increase your multiplier. But you can decrease it and still gain same overclock. Look at the example-

Code:

E7200 , DDR2-800 ram, Multiplier: 9.5

Now @default, I have 266*9.5=2.53GHz

Overclocked, 320*9.5=3.04GHz

Divider ratio I've used is 4:5=4/5. With it, my ram will run at [320*2]/[4/5]=800MHz. Which is the maximum stock ram frequency. So, I'd say my overclock is optimized for its best result because I'm not risking overclocking the ram but I'm having the most of the rated frequency.

What if I used 2:3 divider?

Then the ram would run at [320*2]/[2/3]=960MHz!!! But my ram is rated as 800MHz. So if I do it, the ram will die. So I won't do it. I could overclock the ram but I'm not showing you that since you are new. Just remember, do not go over rated ram frequency. If you had to underclock the ram upto 60~70 MHz to  have a large overclock, you can do it though.

I could've set the frequency and multiplier differently but still I could gain the same overclock using the maximum rated ram.

See-

400*7.5 =3.04 GHz and I'm using 1:1 divider.

So, my ram will run at [400*2]/[1/1]=800MHz. See? I'm not overclocking the ram. But I'd recommend setting the multiplier to its highest value and playing with the FSB and divider. Because some mobos and processors don't like high FSB[Yes, 400 FSB is pretty high].

So, the finally the key is optimizing the performance of the overclock by varying the FSB, multiplier, divider etc. Set voltages other than the vcore to auto. Don't mess with timings. Don't go over 1.25 vcore. Don't overclock ram. Don't jump with the overclock. Ok, now if you did everything properly, you should be stable in OCCT. But do a final stability test with prime95 mix test and run it for 12 hours. It should be successful. 

Welcome, you have successfully done. If you read the guide properly, you should be able to have good overclocks. 

P.S. : If anything can't increase the FSB, up the PCI-E frequency. UPing upto 120MHz is safe.

Warning!: Overclocking can cause damage to your hardware which will void your warranty! Do it at your own risk! I am not responsible for any damage or injury caused as a result of using any of the information in this guide. You are the only one responsible for your actions! But if you can read the manual properly and can do it right, overclocking is a wonderful thing.