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ccolon

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P166 or P133?

I have a Pentium 133, no MMX computer and my friend said he somehow got a hold of a 166MHz chip, so I installed the new one.  The problem is that upon startup, while some elements are different (like the beep sound), the indicated speed is still 133MHz.  I was curious so I used SiSoft Sandra to benchmark and behold it performed less than a 166 and more than a 120.  For the most part, I got no considerable gain I should have received from the chip upgrade.  The only thing new I noticed is that it had MMX support.

My friend believes it is a 166, but maybe there's a jumper that is holding back the performance?  Do I need to change something in the BIOS settings?  SiSoft Sandra indicates that:

Processor: Intel Pentium MMX @ 133MHz
  but
Model Information: P55C Pentium MMX 166-233 2.8V

... so supposedly the model should perform at 166?  At first I thought my friend was just dumb, but I'm not so sure anymore.  Should you need more info, I could send a whole report from Sandra.
Avatar of kahlean
kahlean

for both 133 and 166 MHZ process both fromt side bus are set to 66 MHZ. However 133 runs at 2 X multiplier and 166 runs at 2.5 X. You can check out these setting at your mobo. In order to determine the right multiplier and FSB

In order to check out what type of processor is it you can view from the processor it self where you will see some serial number on the top of it Check out hte first line you will see something like this

8P80502 - 75 SZ994

THe number 75 indicates it is a 75 MHz processor. So if it is a 133 it should state 133 and same goes to 166

Regards

si soft sandra will report the processor speed according to your bios setting as what you seen during POST

It does sound like you have the FSB or multiplier set incorrectly, and this will probably be a jumper or BIOS setting.

Can you post the make and model of your motherboard, and we'll try to sort this out.

If you are unsure, boot the computer, and when the memory test is going press Pause.  Now write down the BIOS string in the bottom left hand corner of the screen (will be something along the lines of "07/06/96 GA7VRT00C-00"), and post that here.
What MOTHERBOARD do you have?  You can't just drop a P166 in place of a P133 and expect it to run at 166MHz.  Your motherboard (hopefully) has a jumper to select BOTH the clock multiplier (for the 166MHz) AND the CPU voltage of 2.8V.  Both of which are different from your P133.

I'd suggest caution at present because you are probably overvoltaging this chip in your present setup.
Actually, your system would be reading the same for both chips if it were simply a faster running chip.  Some of this has been mentioned but I will try to explain for clarity on what is going on.  Because of the architecture in place, the voltage would also have to be adjusted to help prevent burning out this chip.  Some systems actually safegaurd you (for a little while anyway)from damaging your processor by overheating it.  These systems actually will slow down the processor to keep its heat from getting too high.  Have you tested your original processor with this same benchmark program?  Your Friends CPU should support 166 if that is what it is.  As previously mentioned you will need to set the jumpers on your motherboard to support the processors faster speed and to adjust the voltage to keep it from getting too hot.  
agree with above. listening for the snap, crackle & pop if you don't check your jumper settings soon.
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ASKER

Yikes - I guess I'll replace the other chip soon before I screw something up.  I just thought it would be simple enough to just replace the chips.  I wouldn't know where to start messing with jumpers, so how do I find out which ones to set?

SiSoft Sandra reports:

Manufacturer: HOLCO (Shuttle)
Model: (541WUB0D) Intel i430FX PCIset(TM)
Serial Number: 03/05/96-i430FX-2A59CH2CC-00
Chipset: Intel Triton 430FX Chipset

  < System Chipset >
Model: Intel Corporation 82437FX 430FX (Triton)
       Cache/DRAM Controller
Bus(es): ISA PCI
L2 External Cache: 256kB pipeline-burst write-back
Front Side Bus Speed: 66MHz

  < PCI Bus(es) >
    Version:                              2.10
    No Buses:                             1
    Bus Speed:                            33MHz
    Speed Multiplier:                     1/2x

I'm gonna benchmark my old chip, and to be on the safe side, keep it there for a while.
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pbessman

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From the previously mentioed website, I found this.  Your voltages were correct according to this chart.  However, you will need to increase the multiplier from 2 to 2.5.  You are not far Off!

Intel Pentium P54C
 200 MHz
 66 MHz
 3 x
 3.3V or 3.52V
 
Intel Pentium P54C
 166 MHz
 66 MHz
 2.5 x
 3.3V or 3.52V
 
Intel Pentium P54C
 150 MHz
 60 MHz
 2.5 x
 3.3V or 3.52V
 
Intel Pentium P54C
 133 MHz
 66 MHz
 2 x
 3.3V or 3.52V
 
ccolon,

I have an old p133 machine which uses the same mobo as yours. THe highest processor that the mobo can go is 166 mhz.

There are two sets of jumpers that you have to tak care of


The cpu speed ( Front side bus) - JP11, JP12
For both 133 and 166 JP11 is shorted (place a jumper on top of the pins), JP12 is not shorted.

Internal Clock Speed Selectors (Multiplier) - JP13, JP14
For 133- 2.0 X external clock
JP13 is shorted and jp14 is not

For 166 - 2.5 X erternal clock
JP13 and JP14 is shorted

FIY JP11, JP12 is located beside the socket 7 slot where you can see a 'bar' to lock and unlock your cpu. JP13, JP14 is located at the other side of the socket 7 slot




Unfortunately the support for this mobo is no longer available.





 
Avatar of ccolon

ASKER

Ok, I found the multiplier jumper and the main set of jumpers, and it is currently set at the STD setting.  I assume I am aiming to set it like the second MMX setting on the webpage.

The problem is that the P166MMX chip is P55C, which requires a voltage regulator that I don't have and am not about to spend any amount of money on a POS computer anyway.  Too bad ...

Let me know if there is still hope, otherwise I'll close the question soon.  I don't really give a rip of the P166 chip, so I might as well burn it while it lasts as long as it doesn't damage the motherboard and other devices.  At least I'll have MMX for a while (yay).

I might as well upgrade the BIOS while I'm at it, as I have never done so.
i have try to search for the upgrade for this bios as well, but without any success. But with the current bios you can place a MMX processor, as what i said the highest is only P166.  
My links have everything you need including the latest BIOS.
This is the complete link for the P54C and P55C Pentiums for developers,


ftp://download.intel.com/design/intarch/manuals/24142805.pdf

Explaination of section on Voltage, but thats the entire manual above if you want it.
----
7.1.2.2. 3.3V INPUTS AND OUTPUTS
The inputs and outputs of the Pentium processor comply with the 3.3V JEDEC standard levels. Both inputs and outputs are also TTL-compatible, although the inputs cannot tolerate voltage swings above the VIN3 (max.) specification. System support components which use TTL-compatible inputs will interface to the Pentium processor without extra logic. This is because the Pentium processor drives according to the 5V TTL specification (but not beyond 3.3V). For Pentium processor inputs, the voltage must not exceed the 3.3V VIN3 (max.) specification.
System support components can consist of 3.3V devices or open-collector devices. In an opencollector configuration, the external resistor should be biased to VCC3.

All pins, other than the CLK and PICCLK of the Pentium processor (75/90/100/120/133/150/166/200), are 3.3V-only. If an 8259A interrupt controller is used, for example, the system must provide level converters between the 8259A and the Pentium processor.

The CLK and PICCLK inputs of the Pentium processor (75/90/100/120/133/150/166/200) are 5V tolerant. This allows a 5V clock driver to be used for the Pentium processor (75/90/100/120/133/150/166/200). These inputs, however, are NOT 5V tolerant on the Pentium processor with MMX technology. The Pentium processor with MMX technology
CLK and PICCLK inputs are 3.3V tolerant only. A 3.3V clock driver should be used in systems designed to support both the Pentium processor with MMX technology and Pentium
processor (75/90/100/120/133/150/166/200).


--------
From your mainboard site

Pentium P55C MMX Cyrix/IBM 6x86L
   
2.8V by HOT-106 3.3V by Mainboard
 

By indiciation of your mainboard and the Voltage regulator, it shows you are using the 3.3V step, secondly if the P166MMX would have fried very quickly if it was at the full 5V, so you have a MB that will run it as a REGULAR 166 without MMX @ 3.3v (2.8v uses the MMX capabilites)

The BIOS will identify it correctly due to the internal chip Identification or you can use the CPUID utility to make certain what chip it is exactly.

http://appsr.cps.intel.com/scripts-df/Filter_Results.asp?strOSs=5&strTypes=UTL&ProductID=52

This is a VERY RISKY VENTURE and I am NOT SUGGESTING to run a processor without the proper voltage or clock settings.
Do I need to copy and paste the websites here that I post links to?  I see others do that.  I only do it when it is blatantly obvious that people are not reading the links I have provided.  I prefer not to do that for two reasons, theft and wordiness.  
PLEASE follow the LINKS I provided.  It took me quite a while to search them out for you and for you not to use them is insulting to the efforts I have put forth on your behalf.
I will repost them so you can find them

http://www.spacewalker.com/english/faq_e/541.htm#hd001

Find your MULTIPLIER TABLE here:  http://www.spacewalker.com/english/faq_e/541_.htm#hd002
Avatar of ccolon

ASKER

I thoroughly searched those links, pbessman - they were very useful, and I already downloaded the bios upgrade.  It clearly says on the motherboard's specs that it doesn't support the P55C chip that I have (P166MMX).  I'm pretty sure there is no more hope now.  The onboard voltage regulator isn't capable of delivering the dual-voltage the chip needs, and I'm not about to order the HOT-106 voltage regulator.