Good comment Alan... One more thing, the purported purpose of bogomips is for capacity planning and choice of processor for a workload. Under VM, bogomips are really BOGUSMIPS, and are so unreliable (bogus), it can only lead to bogus business decisions.
In the Domino redbook residency in August, there was an "unbeliever" using "top" to look at processor utilization of top under linux under VM. I and another engineer in a different office was able to control his perspective - top's perspective (linux's perspective) on the processor requirement to run top. Before we started playing, top was showing it was using 8%. which was close. It turns out that in a controled environment, we found how to pick a target utilization for top - meaning that we decided we wanted top to report it was using 30% - and made it happen. top was still using 8%, but was reporting over 30%. That was in a controled environment. (ESALPS reported top as using 8%). You can't trust CPU numbers reported by linux when under VM at all. This is VERY easy to prove. It will get worse in an uncontrolled environment. Oh, we're having fun now.... >From: Alan Altmark <[EMAIL PROTECTED]> > >On Tuesday, 10/28/2003 at 08:57 PST, Jim Sibley ><[EMAIL PROTECTED]> wrote: > >> mp2000 - less than 200 bogomips >> 9672-zz7 (g6) 630 bogomips >> 2064-116 (z1) 820 bogomips >> 2084-b16 (Trexx GA1) 2400 bogomips! >> >> The speed of the top of the line zSeries has increased >> at four fold in the last 3-4 years. >> >> It seems that the literature is lagging what is now >> available in the field. Is zSeries more competitive >> now against other platforms than it was four years >> ago? > >Why should anyone give a rats behind about bogomips numbers? A >four-fold increase in bogomips says only that bogomips runs 4 >times as fast as it used to. > >Your question about comparisons of competitiveness is >interesting, but not in the context of bogomips. I would ask if >TCO has improved in the last 3-4 years. The CPU selection is, of >course, only one variable in the equation. > >Alan Altmark >Sr. Software Engineer >IBM z/VM Development "If you can't measure it, I'm Just NOT interested!"(tm) /************************************************************/ Barton Robinson - CBW Internet: [EMAIL PROTECTED] Velocity Software, Inc Mailing Address: 196-D Castro Street P.O. Box 390640 Mountain View, CA 94041 Mountain View, CA 94039-0640 VM Performance Hotline: 650-964-8867 Fax: 650-964-9012 Web Page: WWW.VELOCITY-SOFTWARE.COM /************************************************************/
