Looking on these numbers tells me, that you probably should invest into ifort + mkl. It does not make sense to buy expensive new hardware, but with bad software it runs slower than on a 6 year old PC. Compare your timing with the benchmark page to see what is possible.
k-point parallelization: Please read the UG !!! This is fairly simple. 1:localhost:4 utilizes the mpi-parallel version; you need to put N-lines 1:localhost 1:localhost ... to specify running N lapw1 processes in parallel. Todd Pfaff schrieb: > Peter, thanks for the response. > > I'm getting small speedup from multithreading in libgoto. Here are > timings from the wien2k serial benchmark: > > OMP_NUM_THREADS=1: 195.463u 0.307s 3:15.80 99.9% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=2: 199.565u 0.569s 2:57.40 112.8% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=3: 204.145u 0.635s 2:51.02 119.7% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=4: 211.666u 0.736s 2:49.02 125.6% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=5: 222.604u 1.032s 2:48.41 132.7% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=6: 231.258u 0.927s 2:47.54 138.5% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=7: 243.170u 0.996s 2:46.55 146.5% 0+0k 0+33264io 0pf+0w > OMP_NUM_THREADS=8: 252.584u 0.916s 2:46.57 152.1% 0+0k 0+33264io 0pf+0w > > > I would like explore the k-point parallelization. But when I run > 'x lapw1 -p' it aborts with an error message about being unable to run > lapw1c_mpi. This appears to me like it's trying to run the fine grained > MPI parallel version. I'm not building wien2k with mpi so I don't have a > lapw1c_mpi. I must be misunderstanding something. What am I doing wrong > that's causing it to try to run this lapw1c_mpi executable? > > Which of these are appropriate .machines files to do k-point > parallelization across N cpu cores on a single machine? > > This? > > 1:localhost:N > > Or this? > > N:localhost > > And do I need any of these lines? > > extrafine > granularity:1 > residue:localhost > > Or do I need something else either in .machines or in some other > file or on the command line? > > -- > Todd Pfaff <pfaff at mcmaster.ca> > Research & High-Performance Computing Support > McMaster University, Hamilton, Ontario, Canada > http://www.rhpcs.mcmaster.ca/~pfaff > > On Mon, 11 Aug 2008, Peter Blaha wrote: > >> The program lapw1 spends a large fraction in BLAS-routines, thus it can >> benefit from multithreading of GOTOLIBS (or MKL). >> Setting the variables you mentioned to 2 (or 4) you should see a >> speedup. The improvement may depend on many factors but it will be at >> most about 50%. >> >> Another possibility to utilize the multiple cores is to do k-point >> parallelism. >> Generate a .machines file with 2,4 or 8 times your machine name >> and test the performance with x lapw1 -p. >> On some architectures (with slow memory bus) it can be that only 4 >> parallel jobs give best performance (because the slow memory bus cannot >> feed all 8 cpus properly), on others you can use 8 parallel jobs. >> Sometimes a mixture (4 k-point parallel + OMP_NUM_THREADS=2) is best. >> >> Todd Pfaff schrieb: >>> We're using: >>> >>> wien2k-08.2-20080407 >>> >>> built with: >>> >>> GNU Fortran (GCC) 4.2.3 (4.2.3-6mnb1) >>> GotoBLAS-1.26 >>> >>> and running on an 8 core (2 x quad core) Xeon machine. >>> >>> Can wien2k take advantage of multithreading inherent to GotoBLAS >>> when either GOTO_NUM_THREADS or OMP_NUM_THREADS is set? >>> >>> If so, can someone provide, or direct me to a document about details of >>> the best way to build and run wien2k for such an environment? >>> >>> Thank you, >>> -- >>> Todd Pfaff <pfaff at mcmaster.ca> >>> Research & High-Performance Computing Support >>> McMaster University, Hamilton, Ontario, Canada >>> http://www.rhpcs.mcmaster.ca/~pfaff >>> _______________________________________________ >>> Wien mailing list >>> Wien at zeus.theochem.tuwien.ac.at >>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien -- ----------------------------------------- Peter Blaha Inst. Materials Chemistry, TU Vienna Getreidemarkt 9, A-1060 Vienna, Austria Tel: +43-1-5880115671 Fax: +43-1-5880115698 email: pblaha at theochem.tuwien.ac.at -----------------------------------------
