Messages in this thread | | | Date | Mon, 08 Mar 2004 22:09:16 +0100 | From | Stefan Smietanowski <> | Subject | Re: fsb of older cpu |
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>>> Hello, >>> is there a way to measure/change the fsb of a PII/233/Tonga/440BX while >>> running linux? Google has no answer... >> >> >> >> This is the only one I know about, but it has support for a few >> boards/pll's only. >> >> http://home.iprimus.com.au/mccvals/mvpll/ >> >> Hope it helps, >> Bernd > > > Hello and thank you for your answer. I determined that this cpu has a > fsb of > 66MHz. The reason for my question was that i want to underclock the cpu. > I think it would be better to change the multiplier instead of changing > the fsb. > Therefore i read the msr register 0x02ah, tilted bit 27 and wrote it > back, but > the cpu clock is still the same. Why does that not work? Is it possible to > change the multiplier at runtime at all? >
I'm no expert on the subject but as I recall the processor sets the internal clock (derived from fsb+multiplier) on startup so no matter what you do do the running cpu it won't change it.
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