From mboxrd@z Thu Jan 1 00:00:00 1970 To: Dan Malek Cc: Seungdong Lee , linuxppc-embedded@lists.linuxppc.org Subject: Re: 8240 BogoMIPS References: <39263EA0.69C60AA9@da-san.com> <3926CD15.441C87AB@embeddededge.com> From: Marcus Sundberg Date: 20 May 2000 22:14:39 +0200 In-Reply-To: Dan Malek's message of "Sat, 20 May 2000 13:36:21 -0400" Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Dan Malek writes: > Seungdong Lee wrote: > > 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 ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/