Tricks and Tips

guide to Overclocking a Athlon XP CPU

published on

1. AMD Athlon XP Processor 266/333FSB
2. A very good motherboard such as the nForce2 which allows changing the Multiplier, FSB, Vcore, Vdimm etc in the BIOS
3. Very good memory sticks such as DDR333 for 266FSB CPU and DDR400 for 333FSB CPU
4. A stable Power Supply Unit
5. Patience, tons of it

Overclocking ? an inexpensive way to achieve higher performance by spending as little money.

First things first, read thru the instruction manual for the motherboard and CPU and familiarize yourself with placing the CPU into the socket in the ?right? way, securing the HEAT SINK in the ?right? way, putting in the RAM sticks in the ?right? way.

Some background:

The speed at which a processor runs is the product of the FSB (Front Side Bus) and the Multiplier.
For a 1700+ running at 1466MHZ, it is FSB 133 x Multiplier 11 = 1466MHz. If u still remember 2nd grade math u will know that u cud increase the speed of the CPU by either increasing the FSB or the multiplier. For a thousand reasons known and unknown, CPU manufacturers, suffice to say INTEL & AMD, lock the multipliers on CPUs. AMD until a short time ago did ship out tons of Multiplier Unlocked CPUs making it the most loved CPU among Overclocking enthusiasts. But for the past month or so, even AMD has started to lock their range of CPUs.

The Athlon XP range of CPUs are of two types ? Thoroughbred and Barton, depending on the core-design and the amount of L2 cache each CPU carries. Typically, Thoroughbreds have 256kB of L2 cache and most of them run at 266FSB (core clock of 133 = 266DDR), except a few high end ones such as the 2600+ running at 333FSB (core clock of 166MHz = 333 DDR). The Barton on the other hand carries a L2 cache of 512kB and all Bartons run at FSB 333 and the high end Bartons such as 3200+ run at 400FSB.

If you look at the AMD CPU box packing, you will not find a thing about it being a Barton or a Thoroughbred. d**n AMD doesn?t even mention how much L2 cache the CPU is carrying. The best way to find out if the CPU u r looking at is a Barton or a Thoroughbred is by comparing the length of the core on the CPU. Typically, take a 1800+ in one hand and a 2500+ in another. Look at the core (the small rectangular metal piece at the center of the CPU). Compare. Longer rectangular core is essentially a Barton. The other, shorter one, is the Thoroughbred.

Enough of all that intro. Here?s pure OCing stuff.

Once you are up and running with your system, it is always better to run the components at their default speed to see if everything works. When you are satisfied with ur system and ready to get more juice out of it, here?s what you cud do.

1. With in the BIOS, increase the FSB in steps of Four.

2. Boot into Windows and check for stability. Download programs such as Prime95, SiSoft Sandra 2004, 3D Mark 2001SE to run some benchmarks and stress the components.

3. When u find it satisfactory, go into BIOS and increase the FSB by four more and repeat the steps 1 & 2.

4. You may do this till your system doesn?t boot. Once your system fails to boot in, you may have to reset the jumper on the mother board to clear the CMOS. (check the manual as to how it is done)

5. Then go back into BIOS and increment the FSB in steps of One from the previous value at which the system booted fine.

6. Run the programs, check for stability.

Now you?ll reach a point where anymore increase in FSB even by 1MHz, will fail your system to boot. This is the max speed ur CPU will run at at this Vcore value. Vcore is the voltage that is supplied to the CPU by the motherboard. U may increase this value by a mere 0.25V and then repeat thru the stpes1 to 6. Once u have hit the limit at this value of Vcore, try increasing Vcore by another 0.25V and repeat the steps. Whatever you do, DO NOT INCREASE the Vcore beyond 1.8V for AMD processors.

More speed naturally means more heat. It is always best to install some Monitoring software such as Mother Board Monitor 5 (could be found on the last Digit issue I believe). Check for CPU and mother board temps. CPU temps should never go beyond 60C for an overclocked CPU to last for a long time. More heat means lesser life for the component. Hence investing in a good heat sink is worth the money. But as of now no good heat sink is available in the Indian market. So if u stick with the stock HSF (Heat Sink Fan), then watch your temperature.

Here are a few links from where you may download some programs that I mentioned!

Prime95 ?
SiSoft Sandra 2004 ?
Memtest86 ?
3DMark 2001 SE -

Say your prayers and GOOD LUCK with ur overclocking! Do let us know how u have done!