Thread (2 messages) 2 messages, 2 authors, 2000-05-22

Re: 8240 BogoMIPS

From: Marcus Sundberg <hidden>
Date: 2000-05-20 20:14:39

Possibly related (same subject, not in this thread)

Dan Malek [off-list ref] writes:
Seungdong Lee wrote:
quoted
BogoMIPS value of my board is currently 131.89.
My board is configured to run in 200MHz system clock.
I have not booted my 8240 for a while, and I don't remember the number.
I have another 8240 showing up soon, so I will be back on that before
long and will pay attention to this.  For some reason, I do remember that
with caches disabled this number is _really_ small, like 13 or 18 or
something.
I'm not very familiar with 82x0 processors, but doesn't 8240 use a
603-core? When I worked with a 603ev running at 200 MHz I got
something like 133 BogoMIPS, so then the above value would be correct.
I wouldn't use BogoMIPS for any kind of benchmark.  There have been
plenty of discussions on mailing lists (including linuxppc lists) to
indicate this abosolute number doesn't mean much.  I have many PowerPC
systems running Linux, from 8xx embedded though 7400/G4 systems.  I
certainly can't predict what this number "should" be.
The BogoMIPS can be used for rough sanity-checks when comparing
processors with identical cores and different clocks. For anything
else it's completely useless. And excelent example is that a
Pentium CPU gives a BogoMIPS value of about 1xclock, while a Pentium
MMX CPU gives about 2xclock, even though their real-life performance
is practicly the same.

//Marcus
--
-------------------------------+-----------------------------------
        Marcus Sundberg        |       Phone: +46 707 452062
  Embedded Systems Consultant  |      Email: marcus@cendio.se
       Cendio Systems AB       |       http://www.cendio.com

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