Changing CPU or Overclocking a k6

[blackcatak]

Wait a second!!!, I just pulled the Processor out ( Why I just now did it is beyond me) but I found more info. As follows

VCC Core = 1.8 - 2.2
Fraction = 2X - 4.5X

Does this help at all?

 

[SparkyJJO]

You gotta be careful about upgrading CPUs in laptops because of cooling, you can't really slap a larger heatsink on a proc in a laptop It wouldn't really be a problem going from a 400 to a 500 maybe, but from a 266 to a 500 could pose a real problem, especially considering Compaq is somewhat stingey on cooling (they run hotter than a HP, Dell, and such)

VCC Core = 1.8 - 2.2
Fraction = 2X - 4.5X

Does this help at all?

VCC Core is the voltage, Fraction might be the multiplier?

 

[blackcatak]

I pulled the modem out and there is room for a bigger fan on the side. Also the Heatsink on this thing is Horrible. It will be replaced with something better.

 

[BA]

IOpener knowledge kicking in...

Voltage

K6-2's are mostly 2.2V
K6-2+, K6-3+ are 2.0V
K6-2P was available in a couple voltages I think, around 2.0V

Because of the voltages, and correspondingly heat, I'd really try to get one of the +'s or a K6-2P if at all possible. If you've already got that 550 though, you might as well try it.

The +'s are actually pretty cool, and you've actually got pretty good odds on running one under 2.0V, especially if it's underclocked.

Multiplier
Fraction looks like it's multiplier

CXT cored K6's (which started around 300MHZ) will remap 2x to 6x. That means if you set it to 66Mhz x 2, you'll be running the CPU at 400MHz(66*6).

As KF mentioned, there's software for dynamically changing the multiplier of the +'s; here are some k6+ utilities.

Also, see if you can figure out what chipset is being used. You might be able to use SoftFSB to change the FSB in software too.

Conclusion
Get a K6-2+ or K6-3+. They run cooler. They're faster because of the additional cache. They have nifty software for them.

 

[KF]

Originally posted by: blackcatak
Wait a second!!!, I just pulled the Processor out ( Why I just now did it is beyond me) but I found more info. As follows

VCC Core = 1.8 - 2.2
Fraction = 2X - 4.5X

Does this help at all?

I guess that means there are jumpers for these?

As far as the heat goes, later K6s got cooler due to shinking the core and reducing the core voltage. MY K6-2+ at 550MHz is dead cold. I mean, I can't feel the difference with my finger if the computer is on or off. It has what was a decent sized heatsink about 3 years ago. I'd guess that K6 you have is a special low voltage mobile (and expensive) processor.

With only a FSB of 66MHz, the highest frequency you can obtain will be 6x 66 = 400. At that speed you could probably undervolt later K6-2s and K6-2+ and they'd have no trouble reaching their rated speed.

 

[blackcatak]

Anyone want to go over undervolting real quick.

 

[KF]

Originally posted by: blackcatak
Anyone want to go over undervolting real quick.

Raising the core voltage makes the CPU run hotter. OCers do it to make the CPU capable of going faster. Lowering the voltage makes the CPU run cooler, but it may not be able to make its rated speed. Clocking it slower may allow it to work OK. Most commonly undervolting is done by people who want their PC to be as quiet as possible. They want it to be put out as little heat as possible, so they can use as weak and quiet a fan as possible for cooling. A CPU that is run at a lower voltage also draws less current, and drains the batteries slower.

Overvolting is hazardous to the CPU structure. At some point not much above the rated voltage, the insulating layers break down, destroying the CPU. Undervolting is not a hazard.

 

[blackcatak]

I think I got it. Now after all this I just need to get it back together. Nice learning experience though. Think I might have scared the wife a bit with this project lol. She saw what I was doing and backed out of the office.
OK so I set the bus to 66.6MHz go with the K6-2 550 (still wondering if it will reconize it) Set the CPU type to "Other" and the Multiplier to X4.5. and pray that it Posts.

 

[Assimilator1]

Bear in mind that 4.5x66.6=300MHz ,some what short of 550MHz

 

[blackcatak]

Good point really. Without that higher multiplyer I am locked in the low range with this. hmmmmmmm I'm a little confused. The chip I have now is a 266 running @ 266 with a 4X multiplier @66.6Bus???

 

[Assimilator1]

Seeing as you have the CXT core(350MHz upwards) variant of the K6-2 ,as was said above if you set the mutliplier to x2 it gets remapped as x6 ,so your'll end up with 400MHz which is a bit better

 

[blackcatak]

I missed the X2=X6. hmmm a 400 would be worth it I guess. About a 50% incress. The funny thing on this whole project was my line of thinking "Never upgraded a laptop before, always wanted to" OK so now it will be a 400....... good enough. Untill I can find something else to take apart.