Dear Gromacs developers/users, After suggestions on this mailing list to use intel over gcc compilers, we recently obtained the newest intel compilers (2013.4.183). I was kind of disappointed to find that there is no speed-up at all when comparing a gcc and intel compiled g4.6.2. Is this expected for our hardware, would the speed-up only become apparent when using specific functions (OMP, group-scheme) or am I doing something wrong in the compilation?
An exert fromboth log files is below, the complete logfiles can be found there: http://md.chem.rug.nl/~djurre/logs/N6intel.log http://md.chem.rug.nl/~djurre/logs/N6gcc.log Thanks in advance, Djurre de Jong Log file opened on Tue Jun 25 11:33:25 2013 Host: node041 pid: 13590 nodeid: 0 nnodes: 72 Gromacs version: VERSION 4.6.2 Precision: single Memory model: 64 bit MPI library: MPI OpenMP support: enabled GPU support: disabled invsqrt routine: gmx_software_invsqrt(x) CPU acceleration: SSE2 FFT library: fftw-3.3.2-sse2 Large file support: enabled RDTSCP usage: enabled Built on: Mon Jun 24 20:54:51 CEST 2013 Built by: p238199@login01 [CMAKE] Build OS/arch: Linux 2.6.18-308.11.1.el5 x86_64 Build CPU vendor: AuthenticAMD Build CPU brand: Six-Core AMD Opteron(tm) Processor 2435 Build CPU family: 16 Model: 8 Stepping: 0 Build CPU features: apic clfsh cmov cx8 cx16 htt lahf_lm misalignsse mmx msr nonstop_tsc pdpe1gb popcnt pse rdtscp sse2 sse3 sse4a C compiler: /cm/shared/apps/openmpi/intel/64/1.4.5/bin/mpicc Intel icc (ICC) 13.1.2 20130514 C compiler flags: -msse2 -std=gnu99 -Wall -ip -funroll-all-loops -O3 -DNDEBUG Core t (s) Wall t (s) (%) Time: 10651.270 222.008 4797.7 (ns/day) (hour/ns) Performance: 77.836 0.308 ###################################################################################### Host: node041 pid: 13728 nodeid: 0 nnodes: 72 Gromacs version: VERSION 4.6.2 Precision: single Memory model: 64 bit MPI library: MPI OpenMP support: enabled GPU support: disabled invsqrt routine: gmx_software_invsqrt(x) CPU acceleration: SSE2 FFT library: fftw-3.3.2-sse2 Large file support: enabled RDTSCP usage: enabled Built on: Tue Jun 25 10:25:13 CEST 2013 Built by: p238199@login01 [CMAKE] Build OS/arch: Linux 2.6.18-308.11.1.el5 x86_64 Build CPU vendor: AuthenticAMD Build CPU brand: Six-Core AMD Opteron(tm) Processor 2435 Build CPU family: 16 Model: 8 Stepping: 0 Build CPU features: apic clfsh cmov cx8 cx16 htt lahf_lm misalignsse mmx msr nonstop_tsc pdpe1gb popcnt pse rdtscp sse2 sse3 sse4a C compiler: /cm/shared/apps/openmpi/gcc/64/1.4.5/bin/mpicc GNU gcc (GCC) 4.7.2 C compiler flags: -msse2 -Wextra -Wno-missing-field-initializers -Wno-sign-compare -Wall -Wno-unused -Wunused-value -fomit-frame-pointer -funroll-all-loops -fexcess-precision=fast -O3 -DNDEBUG Core t (s) Wall t (s) (%) Time: 10516.210 219.223 4797.0 (ns/day) (hour/ns) Performance: 78.825 0.304 -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! * Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
