> > Gerasimatos, Dimitrios V (343K) wrote: > > According to SPECfp2006, the X5560 should blow the doors off of the > E5430. > > The X5560 scores 36 while the E5430 scores about 18. > > > > > > However, our own benchmarking using nbench, unixbench, and a home- > grown > > utility (twobod) all show that any differences are attributed to > clock speed. > > I wouldn't use specfp**** ratios as a realistic guide for performance > comparison. As always, use your own code.
What Joe says has a lot of merit. But that said, if your applications have advanced along with the capabilities of modern CPUs, SPECfp2006 is a lot better metric than SPECfp2000, which is a better metric than SPECfp95. Each succeeding generation of SPEC CPU benchmark grows substantially in memory footprint and in the memory bandwidth performance required of a CPU/memory system. I note that nbench and unixbench were last developed around 1996-1997 putting them in the same era of benchmarks as SPECfp95. I see that the application components of SPECfp2006 for which X5560 blows the doors off E5430 (by 2x or more) are: 410.bwaves (CFD), 433.milc (QCD), 450.soplex (Linear Programming), 459.GemsFDTD (Computational Electromagnetics), 470.lbm (CFD). These are CFP2006 applications which I remember as having the most memory bandwidth demand from my days on the CPU committee. Since the Nehalem X5560 can do McaCalpin's STREAM (memory bandwidth, OpenMP 8-thread version) benchmark at about 3x the rate of Harpertown E5430, that explains a lot of the difference. If you applications have a small memory footprint, or have great cache re-use, you probably don't need the newer generation of CPU. -Tom > If your code shows 2x, > great. If not, then attribute the specfp**** to what they are > (marketing numbers, with some grounding in reality, but not a firm > comparison metric for dissimilar apps). > > > > > > -- > Joseph Landman, Ph.D > Founder and CEO > Scalable Informatics Inc. > email: [email protected] > web : http://scalableinformatics.com > http://scalableinformatics.com/jackrabbit > phone: +1 734 786 8423 x121 > fax : +1 866 888 3112 > cell : +1 734 612 4615 > _______________________________________________ > Beowulf mailing list, [email protected] sponsored by Penguin > Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
