Re: fsb of older cpu

From: Stefan Smietanowski
Date: Mon Mar 08 2004 - 16:11:00 EST

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.

Hope it helps,

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.

// Stefan
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