From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <39289DA5.F0A5B8FF@da-san.com> Date: Mon, 22 May 2000 11:38:29 +0900 From: Seungdong Lee MIME-Version: 1.0 To: Marcus Sundberg CC: Dan Malek , linuxppc-embedded@lists.linuxppc.org Subject: Re: 8240 BogoMIPS References: <39263EA0.69C60AA9@da-san.com> <3926CD15.441C87AB@embeddededge.com> Content-Type: text/plain; charset=EUC-KR Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Marcus Sundberg wrote: > 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. > Good information. But, why it is 133 BogoMIPS? I still think that the correct value is 400. > > > 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. > Maybe it is because of the difference in superscalar architecture. -- Seungdong Lee > > //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/