Re: BogoMIPS Rating on MMX

H. Peter Anvin (
1 May 1997 16:33:48 GMT

Followup to: <>
By author: The SethMeister <>
In newsgroup:
> Hi yall,
> I have a Pentium 166 MMX overclocked to a 200. Before I found out that I
> had the voltage level set too high for the core (3.5V), I was getting a
> bogomip rating of ~398 (at the overclocked setting) and ~338 at the
> non-overclocked. I since set the voltage to the recommended 2.8V and the
> BogoMIP rating for the overclocked 200 has dropped to 298. Is it possible
> that the voltage has something to do with it (I doubt it, but hey (I was
> wrong before ;)))?

Actually, CMOS logic does operate faster at a higher voltage. Of
course, if you operate above the spec voltage you take the risk of
letting the magic smoke out, either by zapping the channels of the
transistors or by overheating the chip.

That being said, this would only affect your chip if the clock
frequency was correspondingly incresed as well. Possibly changing the
voltage also changed the internal clock multiplier.


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