A newbie’s guide to Overclocking an Athlon XP CPU


Jun 3, 2003
Mask get Fredi to lock this thing.

-Intel PIV 2.6C @ 3.575G -Asus P4P800 -OCZ Copper 2x256 4000EL memory @ 275mhz 3-4-4-8 -Sapphire 9800np @ 432/760 -SB audigy -120G Maxtor Diamond Plus9 S-ATA150 hdd -450 Enermax PSU


Apr 23, 2003
<b><font color=red>CAUTION!!!</font color=red>

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. 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 – <A HREF="http://mersenne.org/freesoft.htm" target="_new">http://mersenne.org/freesoft.htm</A>
SiSoft Sandra 2004 – <A HREF="http://www.sisoftware.net/sandra" target="_new">http://www.sisoftware.net/sandra</A>
Memtest86 – <A HREF="http://www.memtest86.com" target="_new">http://www.memtest86.com</A>
3DMark 2001 SE - <A HREF="http://www.futuremark.com/download/" target="_new">http://www.futuremark.com/download/</A>
MotherBoard Monitor 5 - <A HREF="http://mbm.livewiredev.com/" target="_new">http://mbm.livewiredev.com/</A>
Say your prayers and GOOD LUCK with ur overclocking! Do let us know how u have done!

If you are looking for some Batch numbers for the locked/unlocked Bartons, this is a gr8 link from <A HREF="http://forum.oc-forums.com/showthread.php?s=a75975397096a35bd3fb4900a819e497&threadid=244237&perpage=30&pagenumber=1" target="_new"> <b>Overclockers Forums</b> </A>

<b>I know this Guide needs some improvement and corrections. Feel free to point them out. Suggestions and Criticisms are most Welcome!</b>

I also wanted to post the batch numbers of the uber OCing chips. I do not have much idea about those. SO anyone care to help me in this regard? Also, it would be great if info about HSFs for Overclocking is included. I do not have any idea of the good HSFs. So i need your help there too.

<font color=red>
Barton 2500+ @ 10x222 = 2225MHz
A7N8X Dlx Rev 2.0
Kingston Hyper-X 2x256MB DDR500 @CL2.5-4-3-7
IBM 80GB + Seagate SATA 2x120GB
MX440 64MB/4X GPU/Memory : 388/513MHz
</font color=red>

<b><font color=red>A word of caution, read thru <A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=680348#680348" target="_new">Scottchen's AthlonXP melting point! experiment</A></b></font color=red>

AthlonXP melting point! Reply to this post

I was really goddamn bored, so i've decided to find out what exactly is the melting point of an AthlonXP TbredA chip. I got a 1700+, a thermal monitor rated to handle up to 150C. Excellent torture time, now with a SLK900U placed on the thermal probe(thermal taped to the CPU), no mounting, had to do that since comp won't boot without heatsink.

Next up was a little bios tuning on the A7N8X-X, Vcore at 1.85, frequency running at 12.5x166. Windows boot, probe tells it's at 53C, MBM5 tells it's at 51C, so i'll just say margin of error of 5C. Damn it that SLK900U's too good, without fan it's handling. Fine be that way Thermalright, turned on prime95 pulled the heatsink off.

2 seconds...
3 seconds...
4 seconds...
I'm suprised it's still alive after 4 seconds, at 107C!
5 seconds...
Computer turns off, smells horrible(melted silicon). The CPU is MELTED MUHAHAHA.

So for all of you overclockers wandering what's the melting point of an AthlonXP chip here's your answer 126C +-5C.
<P ID="edit"><FONT SIZE=-1><EM>Edited by TheMask on 05/02/04 00:56 AM.</EM></FONT></P>


Aug 1, 2005
Just wanted to post my specs:

ASUS A7N8X-E Deluxe MB
ATi Radeon X850 Pro
AMD Athlon XP-M 2600+ @ 2.4Ghz (11x218Mhz) Vcore @ 1.65V
2x512Mb Corsair C2PT @ 2.5-3-3-6 @ 2.7V
Thermalright SI-97 Heatsink w/ Zalman 90mm Fan

CPU Idle: 107F/42C
CPU Load: 118F/48C

I have not tested with Prime95 because last time it wasted my time (At 11x200Mhz, it was stable for 28 hours, but crashed on Halo in 2 min...) It has been COD2 stable for over several hours at once, and has not crashed on other games.

Also, if you want a good HS/F, I think Thermaltake and Thermalright offer the best choices.


Jun 9, 2006
i ve got a reeeeeeeeeeeeeeeeeally old crappy pc and i would like to get whats left out of it b4 i buy a new one since i luck of founds at this period.so i would like some oc suggestions about my toaster in case i can improve it a bit :p
my specs r :
pros/athlon xp 1600+
mobo/epox EP-8KHA+
hd/WD 40 giga
ram/2x128 twin moss + 1x256 lifetime no-name
vga/gForce 2 Ti (oc about the vga r also welcomed :p )

im not expecting mirracles but any cool suggestions would be most welcomed :D


May 4, 2006
Nice guide, but doesnt realy adress the multiplyer. heres my little OCing project



Apr 10, 2007
Hey guys!
I got a Barton 2500+ and id like to increase the FSB.
If i do that,dont i get in trouble the vga and the RAM?
Ive heard there is a connection between them.
Can anybody inform me plz?
Thank you


Jan 21, 2006
They are still fun to play with. I have a Barton 3000 (333 FSB) and had the bus up to 193 (2.509 GHZ) the voltage was set at 1.85 to get it stable on a Asus A7N8XE Deluxe. Just kinda fun tinkering around.


Apr 15, 2007
Help Please

Thanks for the guide very helpfull, tell me now I have an
AMD Athlon 1.25Ghz
256MB Ram running at 266
On a MSI KT600 Delta Series Main Board

Now I have managed to colcok this puppy to 1.66Gh
using the BIOS' High Performance Settings (ie push F7 for these settings)
Things where hunky dorie for like 5 days temp was alright at average 52C a jump from 43C but still safe from what I've read and been told. But just recently I get BLUE SCREEN (my heart stopped I'm sure). Now back to default settings things are running still (phew) but the cpu now sits at 50C not the original 43C. Thats my first query.

How fussy are these MSI mainboards when it come to memory, cos when I used that F7 option my DDR clock jumped from 266 to 400. thing is months before my overclocking experimenting I went to go buy some memory DDR400 and it would not see it even with the BIOS set to auto.

Well that is really it

Cheers Look forward to ure reply


Apr 15, 2007
Not to sure which memeory you talking of but here's the memory story in depth.

I decided to try buy some memory but since I bought this PC off a mate I don't know exact specs. So I went to the PC shop with my PC to test their DDR400 ram. Nothin happened. Did not see it at all, at that time though I did not know where to change the speed in the BIOS. And when testing it was set to AUTO by default.

Now after experimenting with the overclocking, and finding the default high performance settings work ok, I see that my Memory runs at 400 (This pops up right at the begging of my PC power up when it does the Memory check) as apposed to the original 266. Now that I think of it.......is the memory I have (1x512Mb Dimm Hynix made) actually DDR400, or is it just the BIOS forceing the setting?

Hope my writting ain't to confusing

Thanks any help muxh appreciated

Hope this helps


I remember my old s754 mobo used to set the memory speed lower by default. 333mhz if I remember correctly. I had to set in by SPD or manually in the BIOS as Auto set it much lower (including loosening the timings). Its for compatibility reasons I think. It is likely that this is what yours is doing. It was a VIA chipset too, if that has anything to do with it.