Subject: Re: probing CPU speed?
To: Andrew Gillham <>
From: Dave Sainty <>
List: port-i386
Date: 11/21/1998 11:00:09
Andrew Gillham writes:

> Uhmm, there are two different requests in this thread.  One for some
> kind of "BogoMIPS" type rating, and one for the apparent clock speed
> of the CPU.  I don't care particularly for the BogoMIPS rating, but
> I definitely would like to know what kind of CPU is in the box.

It seems the issue really is that people want the "name" of their
hardware.  BogoMIPS and CPU MHz are pretty similar numbers, neither
gives particularly useful information in the general case, but is some
kind of metric of CPU speed.

The reason people want MHz and not BogoMIPS is because its part of the
_name_ of a piece of hardware in their machine, and it is nice to know
what physically resides in the machine.

If it was easy to probe this, I doubt the question would come up, it
would just be dumped as part of the startup probe.

Some BIOSes print the information, but they are using their privileged
position to do so (tuned to the motherboard hardware).  If you are not
a BIOS then there isn't a way to do it.

But the fact of the matter is that it can't be done.  Any such
guesstimate of CPU clock rate is always going to degenerate to a
BogoMIPS like quantity that people hope will get somewhere near the
true clock rate.

There are (already stated) userland programs to do this.  If you want
a clock rate guess, use that.  It will be similarly accurate.

If clock rate could be simply probed on PC's, it would be nice to
print.  It can't.