Tualatin CPU on i440BX chipset based mainboard

The system I used :

Mainboard : ABIT BX133 RAID

Processor : Celeron 1.0A (Tualatin 256Kb L2 cache)

Cooler : ADDA 6x8->8x8 with 8x8 SUNON PTB1 fan

RAM : 256mb SDRAM Corsair PC150 2-2-2

VGA : ASUS V7100 PRO OC @280/290mhz

The story :

I wanted to put a Tualatin CPU on my ABIT BX motherboard but BX chipset isn't Tualatin ready

I knew that there were Powerleap adapters but they were expensive and I couldn't find them

A few days ago I noticed about some modification to the cpu pinout that could let me to fit this chip on my motherboard without using any adapter.

So I worked hard to find on the web and on HW forums any information about this mod.

When I took the know how to do this job I began working around my new Celeron 1.0A and here you are the results ....

 Some Pictures :

Theory : here you are the interested pins for the mod.

RED pins must be insulated , they shouldn't be conncted to the socket

BLU pin (AK26) must be connected to the RED called AK4 directly on the CPU

GREEN pins must be connected tohether to give an appropriate voltage to the core


Practice : how I did it on my cpu

I did not wanted to modify my motherboard so i worked only on the CPU

First i pulled off the red pins and took away the slug upon the core to get a better temperature  :


Then I put it on the mainborad directly , because i red that it could work without other mods.

It booted! GREAT! the default voltage was 1,45v with no pin adjustement so i try keeping it so

But it was instable, I coludn't go into windows so I decided to connect also the other pins using conductive silver paint :


 I let it dry and then i gave a second hand of paint to be sure to obtain a good conductivity (used a tester)


It was a hard and sharp job !

I had to use a lens and a thin wire as a brush, and prayed to not waste the cpu connecting also the wrong pin ......


Then i connected Vid4 (AK36) and Vss (AM34) in the same way

Ii decided to cover again the core with the slug to protect it from breaking

and used some silver compound on the CPU core and engine black sealant as glue all around ,to dry it in the right way I took an old slocket and

a strong heatsink clip with a copper base to push it firmly:


After this treatment  it looked as a original never opened CPU !


Now the system with the modified CPU works stable and fast, after connecting also Vid2 to Vid1 (because Vid1 is yet connected to Vss)

default core voltage changed from 1,45v to 1,65v and the max voltage in bios changed from 1,7v to 1,9v.

Here you are a shoot of my system parameters :

(Updated on March 15th 2002,after lapping the CPU slug till it become a mirror, note SETI client running in background...)

 WOW I really do love this CPU and I'm very happy !Finally I get a very fast Tualatin on my BX133 mobo!

Here you are also some score I did :

Super PI : 1 min 40 sec

3dmark2000 : 8018 3dmarks

3dmark2001 : 4013 3dmarks

Q3A PR 1.17 : 98,8 FPS (1024*768*32 high details)

Maybe it could do better but I'm very satisfied now!

Special thanks:

All I wrote in these pages is what i could learn thanks to the great work and care of many guys  in a few HW forums,

here you are some links where i found very useful tricks about the Tualatin pin modding :






Other links are listen in the pages I linked above

Disclaimer :

This is only what I did on my system , not a guide to "how to put a Tualatin cpu on a system not Tualatin-ready"

I don't know if it works on other motherboards or on other chipsets,don't ask me for this , I simply don't know!

For further informations refer to the links i gave above.

have fun!