Subject: Re: probing CPU speed?
To: Chris G. Demetriou <email@example.com>
From: Jonathan Stone <jonathan@DSG.Stanford.EDU>
Date: 11/18/1998 19:45:59
>And for what purpose would it be nice?
I know you'll correct me if i'm wrong, but you seem to think the
*only* purpose of CPU speed is as a metric of overall system performance.
For which I agree CPU clock rate is not an accurate measure.
yes, sometimes people who dont know any better use it for that.
I can think of 3 plausible, legitimate uses without even blinking:
a) mapping cycle-counter measurements of *real* code
execution to wall time.
b) calibrating use of cpu cycle-counter as NTP clock source.
c) ascertaining whether one of several externally-identical
machines has been re-clocked or overclocked.
say, in a lab. These things happen...
I use the first 2 on mips. (I need to recoutn delay slots in the
calibration loop that counts cycles between mcclock ticks: egcs
changed it. But if I leave it alone long enough, NTP will eventually
settle down and tell me the real numbers. :->)
so, if someone really does want to know the CPU clock rate for
something useful, why not let them?
Arguing that `I dont see a legitimate use for this, thererefore you
cannot have any legitimate use for it'-- well, do we really want to be
If you dont want it to be misused, fine, make it an option or something.