# Help with "overclocking" Cyrix MII



## Addy (Oct 21, 2007)

This Cyrix is rated at 366 MHz, but with the current motherboard it is in, it's set to 233 MHz. I'm not really trying to overclock, but just to get the CPU up to the normal speed. I have looked all over the motherboard, and in the CMOS, but I cannot find any multipliers/etc. What would I have to do to modify the multipliers?

Here is some information about the computer I am working on:
http://storage.us.to/cpuz.html

The memory is not shown there, it consists of 4 SIMMs, but I have forgotten the sizes.

Thank you in advance.


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## linderman (May 20, 2005)

that cpu and motherboard were not good overclockers at all!


I would leave well enough alone, unless you want to attend a computer funeral


otherwise

http://files.extremeoverclocking.com/file.php?f=189


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## Addy (Oct 21, 2007)

I am aware that Cyrix is terrible for overclocking, but I am not trying to go over the clock speed, just to get to it or somewhere close.

I found front bus jumpers and CPU multiplier jumpers, fiddled with them all for about an hour, but I could not reach anything over 233 MHz.


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## Addy (Oct 21, 2007)

According to Windows, the CPU is running at 266 MHz, even though the boot screen says 233.


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## 1 g0t 0wn3d (Jan 31, 2007)

use cpuz to tell


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## Addy (Oct 21, 2007)

CPUZ also said the speed was 266.6 MHz.


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## 1 g0t 0wn3d (Jan 31, 2007)

then thats the speed


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## Done_Fishin (Oct 10, 2006)

clock speeds back then were set by 2 factors 
1) the CPU speed and 2) the multiplier 

some boards had the multiplier in BIOS whilst others had it on board with jumpers.
I remember a few boards where the over clocking required that a few extra jumper pins be added after it was found that the required multiplier factor couldn't be reached.
Some SOYO boards also required a special jumper (something to do with bursting) or the board would seize up when using Cyrix CPU's.

so your first question should be .. whats the max multiplier I can get on the board .. if it doesn't allow you to switch from 66MHz to 75MHz or 100MHz whilst playing with the multiplier then your goose is cooked. You'll need to research the multiplier chip and see if there's a way to mod the board to get your output.


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## linderman (May 20, 2005)

do you have the motherboard manual ? thats where I would start ?




look on the motherboard and you will see printed in white lettering the brand and model of the board >>>>> generally somewhere around the PCI slots


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## Done_Fishin (Oct 10, 2006)

if you get stuck .. look for the BIOS number as your PC goes through post .. According to your link in your first post its an AMI BIOS and model no. PT2011 from First International Computer Company.
Websites like Wims BIOS page will help you identify it better and perhaps link you to a site for a BIOS upgrade ( better to write a new chip and replace it rather than upgrade the existing chip. That way you can recover if & when it goes wrong!!)

I would also like to say that you are a man of great courage trying to run XP on that board .. you must have the patience of a saint to wait while it boots :grin:


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## Addy (Oct 21, 2007)

It actually boots XP faster then my main computer, but that's because it's not running like 4 servers 

I already sent an email to FIC about any possible BIOS updates, and when I checked the motherboard, the maximum that the front bus could go to was 66.6 MHz.


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## Done_Fishin (Oct 10, 2006)

Then you're probably aware that you need a multiplier of 366/66 in order to get your full CPU clockrate. which means that you're looking for multiplier of 5~6. It would appear that the motherboard only has 3 clock settings from info picked up on the site. If you know anything about electronics you could check what Chip is used for the multiplier function and see if there is any way to "modify" the input to allow a different multiplier setting. Most of the time this is done logically by grounding specific INPUTS.

Links within FIC site 

*site for FIC PT2011*

*Cyrix CPU FAQ here*

*PT2011 FIC PT-2011 PCI SYSTEM BOARD - BOARD LEVEL COMPATIBILITY TEST REPORT
*


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## Addy (Oct 21, 2007)

The motherboard shows the multiplier max is 4, so my only other option would be to raise the front buffer, which I think is also maxed out at 66.6. Oh well, thank you for all your help!


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## Done_Fishin (Oct 10, 2006)

Sorry I can't do much else for you... have you tried any overclockers forums to see if they have anything in their archives?? Depends just how important this is to you and how much time you want to spend on it! 

Remember also that there is a possibility you'll get the speed changed but the motherboard will then crash due to the BIOS timing limitations. I have a PIII 600MHz board that would work with an 800MHz CPU ... ONLY if the CPU was within board specs .. as soon as I forced it to 800MHz it would work but crash frequently. The first errors it gave me would be that the registries were corrupt. It had problems reading the hard drive properly at the new speed. 

As Mr Murphy said .. any small modification that is made somewhere causes a chain reaction of further modifications that require to be done! ( and every mod then brings forth many more )


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