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Hi Stephan, Did you look at total memory usage on the machine as you added the cores? Was it linear, or linear with a negative intercept (indicating a great deal of shared code between the processes)? Since you can't predict which jobs will be running on any one machine, this probably isn't a relevant number for this discussion, however, I'm curious to know how well ATLAS jobs do in this circumstance. Cheers, Gordon. > -----Original Message----- > From: [log in to unmask] [mailto:owner- > [log in to unmask]] On Behalf Of Stephen J. Gowdy > Sent: Tuesday, August 21, 2007 4:42 PM > To: ATLAS SCCS Planning > Subject: eval01 comparison > > Hi All, > So I've ran 1, 2, 4 and 8 jobs simultaneously on eval01. I also > ran one job on yakut04 to compare CPU speeds (so only look at CPU time > for that, wall time is probably not good to compare in this case). I've > attached the spreadsheet with the numbers if anyone wants to look at > them. > The basic conclusion is that the new Intel CPU's GHz are worth > about 15% more than the Opterons (this is a big change from the P4s, > where IIRC BaBar say a 30% drop). Overall we loose about 5% when > running eight jobs on the same machine, with some coming from less CPU > efficiency and more system time used (some more user time too, > particularly in going from > 4 to 8 jobs). > The job run was a simulation job which is the most CPU intensive > part of the ATLAS job suite. (only 3 events which took about 30 > minutes). > > regards, > > Stephen. > > -- > /------------------------------------+-------------------------\ > |Stephen J. Gowdy, SLAC | CERN Office: 32-2-A22| > |http://www.slac.stanford.edu/~gowdy/ | CH-1211 Geneva 23 | > | | Switzerland | > |EMail: [log in to unmask] | Tel: +41 22 767 5840 | > \------------------------------------+-------------------------/