Some people had asked for more details: NAS suite version 3.2.1 Test class was: B Units are Mops (Million operations per second) see the NAS docs for more information
-- Doug > I like answering these types of questions with numbers, > so in my Sept 2007 Linux magazine column (which should > be showing up on the website soon) I did the following. > > Downloaded the latest NAS benchmarks written in both > OpenMP and MPI. Ran them both on an 8 core Clovertown > (dual socket) system (multiple times) and reported > the following results: > > Test OpenMP MPI > gcc/gfortran 4.2 LAM 7.1.2 > ------------------------------------ > CG 790.6 739.1 > EP 166.5 162.8 > FT 3535.9 2090.8 > IS 51.1 122.5 > LU 5620.5 5168.8 > MG 1616.0 2046.2 > > My conclusion, it was a draw of sorts. > The article was basically looking at the > lazy assumption that threads (OpenMP) are > always better than MPI on a SMP machine. > > I'm going to re-run the tests using Harpertowns > real soon, maybe try other compilers and MPI > versions. It is easy to do. You can get the code here: > > http://www.nas.nasa.gov/Resources/Software/npb.html > > -- > Doug > > > > > > > > > >> On this list there is almost unanimous agreement that MPI is the way to >> go >> for parallelism and that combining multi-threading (MT) and >> message-passing >> (MP) is not even worth it, just sticking to MP is all that is necessary. >> >> However, in real-life most are talking and investing in MT while very >> few >> are interested in MP. I also just read on the blog of Arch Robison " TBB >> perhaps gives up a little performance short of optimal so you don't have >> to >> write message-passing " (here: >> http://softwareblogs.intel.com/2007/11/17/supercomputing-07-computer-environment-and-evolution/ >> ) >> >> How come there is almost unanimous agreement in the beowulf-community >> while >> the rest is almost unanimous convinced of the opposite ? Are we just >> tapping >> ourselves on the back or is MP not sufficiently dissiminated or ... ? >> >> toon >> >> >> >> _______________________________________________ >> Beowulf mailing list, [email protected] >> To change your subscription (digest mode or unsubscribe) visit >> http://www.beowulf.org/mailman/listinfo/beowulf >> >> >> !DSPAM:4759a800241507095717635! >> > > > -- > Doug > _______________________________________________ > Beowulf mailing list, [email protected] > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf > > !DSPAM:475c325f61251246014193! > -- Doug _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
