Clock multipliers/dividers?

[CTho9305]

How do they work? Are they hardware or software? BIOS or the pll?

 

[chriscraft]

Multipliers,(built and LOCKED into the CPU normally these days), just take the M/B set FSB and does simple multiplication.

A PIII 500Mhz is built to run on a 100 mhz FSB M/B, and it has a 5x multiplier built into it. So, 100Mhz time 5 = 500Mhz. The motherboard runs at 100Mhz and the CPU runs at 500Mhz in this case..

All Intel CPU's built before the PII 300 were unlocked, so are all AMD K6 series CPU's, and you can also modify AMD Thunderbirds and Durons to make them unlocked also.

With a motherboard that will allow you to change multiplier setting, it is possible to run some CPU's at a speed higher than they were sold at. (One type of Overclocking)

All AMD Duron CPU's will run around 900Mhz, no matter which model you buy. Along with a good overclocking M/B, you can take a $40 Duron and get some of them up to 1 Gig.. just need a little higher voltage to the CPU, and a good heat-sink-fan,(HSF).

If you don't overclock, it's all automatically sensed anyway...so this is basically hardware..

But there is also some software programs for the AMD K6 series CPU's that will allow changing speed on the fly while in windows. Also I think most all of the NEW Laptop CPU's,(Mobile CPU's), have thus feature built into them. That's how they save battery power, software lowers speed,(multiplier), when not under heavy use and increases speed when needed...

 

[chriscraft]

ps: depending on the M/B brand and Model, you can change the mulitiplier setting in the BIOS or on jumpers on the M/B.

here is an interesting read

http://www.anandtech.com/showdoc.html?i=1345&p=3

 

[CTho9305]

thanks, but I was actually asking a more technical question. I understand all you said there... I want to know how you turn a 100mhz pulse into a 700 (like in my tbird, for example) and how you turn a 100mhz fsb into a 33 pci. I was wondering if it would be possible to write a patch or bios update that had more PCI dividers (K7V does'nt have a 1/4 divider, so if I run at 133 fsb I get a 44 PCI). that problem led me to wonder about multipliers/dividers in general.

edit: its a slot a tbird 700 on a k7v - k7v's aren't made for a 133 fsb