• 14 Dec 2007, 22:26 • Tutorials
Overclocking – Intel: Pentium 4, D, M, Core Solo, Core 2 Duo, Core 2 Extreme and Celeron D
Prime95 or HERE or HERE
Bigger overclocking is only possible with good cooling. So get a better CPU-FAN or even a watercooling.
First you have to find out your max Vcore. Here you can find them. Check also your max. Temperature which is also shown at the Intel Spec Finder (link above “Here” xD).
The first you have to know is:
CPU-clock = FSB*CPU-multi FSB (Front Side Bus)
RAM-clock = FSB/RAM-dividend*RAM-divisor
e.g. ¾ 3 = dividend, 4 = divisor
What we’ll do at overclocking is to raise the FSB to get a bigger clockspeed.
You can also raise the CPU-multi but this is only possible at the Extreme Editions.
Front Side Bus
Often the FSB is denoted at the fourfold speed because it is “Quadpumped” (http://en.wikipedia.org/wiki/Front_side_bus).
But you have to calculate with these numbers.
133MHz = P D 805; Celeron D;
166MHz = C2D T5x00; C2D T7x00; Alle Core Solo und Core Duo;
200MHz = P 4 5x0; P 4 6x0; P D 8x0; P D 9x0; Core 2 Duo E 4x00
266MHz = Core 2 Duo E6x00
333MHz = Core 2 Duo E6x50, Core 2 Extreme QX6850, QX9650
There are a lot of differences on the M Series. So plz have a look http://en.wikipedia.org/wiki/Pentium_M]HERE[/url]
You get the multiple with the calculation at the top (CPU-clock = FSB*CPU-multi).
Intel® Core 2 Duo E6850 Conroe
Clock = 3.0 GHz
333MHz*9 = 3000MHz
cause: 1333MHz (FSB) / 4 = 333MHz
multi: 9x both @ CPU-Z
There is also an 1:1 divider. FSB and RAM-Clock are running synchronal then.
e.g. 266MHz/2*3 = 400MHz
It’s just 400MHz because DDR2 is sending 2 data packets per cycle (http://en.wikipedia.org/wiki/Double_data_rate).
How to input the RAM-divider will be shown at the overclocking part.
• There is no smaller divider as 1:1 at the 956 chipset
• At the 650i/680i/780i chipset you can choose “unlinked”. Now there is no coherency between the FSB and the RAM. If it’s set to unlinked you can set the MHz optional.
1. Lock the VCore at the BIOS.
2. Set following @ the BIOS, too:
• PCI-Clock: 33MHz
• PCI-E Clock: 100MHz (66MHz @ AGP)
• RAM-Clock/RAM- divider: to the next smaller level
Overclocking 1st Part
First i’ll show you a whole overclocking process on an example:
Intel® Core 2 Duo E6600 2.4GHz, DDR2 800MHz
CPU: 266MHz*9 = 2400MHz
RAM: 266MHz/2*3 = 400 MHz
FSB to 275MHz
CPU: 275MHz*9 = 2475MHz
RAM: 275MHz/2*3 = 413MHz
413MHz aren’t that bad for the RAM but if you get higher the PC couldn’t start or the RAM could even get fucked up. So be carefull with this!
To be sure we’ll set the divider to 1:1 and it’ll look like this:
275/1:1 = 275 MHz
But if this isn’t enough for you, you have to raise the FSB again:
FSB to 285MHz
CPU: 285MHz*9 = 2565MHz
RAM: 285MHz/1*1 = 285MHz
RAM: 285MHz/2*3 = 427MHz for good RAM – no problem
!!! JUST RAISE THE FSB 5-10MHz AND GO SLOWLY HIGHER!!!
Check always the temperatures @ SpeedFan and stop if it’s getting to high! (more at the 2nd overclocking part)
Overclocking 2nd Part
The act of Overclock
1. Raise the FSB 5-10MHz @ BIOS
2. Start Speedfan (under windows) and check the temperatures. The CPU temperature shouldn’t be above the set temperature (set temperature = max. temp. -10°C)
3. Run prime95 for 30minutes. (more under Prime95)
a) If Prime isn’t telling a problem repeat step 1-3 till prime tells the first error. After this go on with step 4
b) If Prime is telling a problem go on with step 4.
4. Raise the VCore about 0.025 Volt. You should raise the VCore max. about 10%!
5. Run Prime (look at temperatures!!!)
a) If Prime isn’t telling a problem repeat step 1-3.
b) If Prime is telling a problem repeat step 4-5.
If your PC doesn’t boot after these changes you have to do a “Clear Cmos”(BIOS-Reset).
1. plug of your PC from the power supply
2. Switch the jumper for 5-10 seconds. After this switch it back again. (more at your MOBO-Guid)
3. Now the settings in the BIOS are resetted and your PC is able to boot again. Don’t forget the change your settings angain.
You repeat these steps untill you reach the set temperature of your CPU, you raised the VCore about 10% or the RAM reached its limit.
If you reached this point, you have to set the FSB to the last stable level. Don’t forget to change the RAM-divider maybe again.
Overclocking 3rd Part – Extreme Editions
Thats the easiest way to overclok you CPU. You just have to raise your CPU-multi and the RAM will raise also.
You have to run the Torture Test under Options/Tortour Test….
Settings like this:
If you are running a Dual-Core processor you have to copy the directory and run prime95 twice.
1. download BIOS and copy to a bootable CD or Floppy
2. at booting you have to push a combination of some keys (look at your MOBO-Guid)
3. now flashing-act starts
4. at the end the PC will reboot and the screen maybe will stay black
5. now you have to plug of your PC from the power supply. Switch the jumper for 5-10 seconds. After this switch it back again. (more at your MOBO-Guid)
6. reboot – thats it
Finding the limit
1. max. FSB
For this you have to lower your CPU-multi and raise the FSB. It’s not bad if your CPU is running under the standard-clock-speed.
Intel® Pentium D 820 2.8GHz Smithfield
FSB: 200MHz with lower CPU-multi
200MHz*10 = 2000MHz
raiseing the FSB to 230MHz
230MHz*10 = 2300GHz
Do this until your PC doesn’t boot again. If it doesn’t you have do do a CMOS-Reset.
Look at the temperatures and run prime, too!
You can choose between a bigger FSB or you change the divider. If you change the divider it’ll be a big overclocking! If you want to make it step by step you should choose to raise the FSB. But: Watch the CPU-multi, or you’ll overclock it, too. So lower the CPU-multi and nothing can happen.
You can test your RAM with prime95 again, but now you choose the blend-test.
These statements are without guarantee.
I don't take on damage at your hardware.
I don't take on damage at your hardware.