performance measurements
Each table row shows performance measurements for this Fortran Intel program with a particular command-line input value N.
| N | CPU secs | Elapsed secs | Memory KB | Code B | ≈ CPU Load |
|---|---|---|---|---|---|
| 500,000 | 0.23 | 0.23 | 252 | 1172 | 4% 0% 4% 100% |
| 5,000,000 | 2.29 | 2.29 | 252 | 1172 | 0% 0% 0% 100% |
| 50,000,000 | 22.89 | 22.89 | 252 | 1172 | 0% 0% 0% 100% |
Read the ↓ make, command line, and program output logs to see how this program was run.
Read n-body benchmark to see what this program should do.
notes
Intel(R) Fortran Compiler XE for applications running on IA-32, Version 13.0.1.117 Build 20121010
n-body Fortran Intel #4 program source code
! The Computer Language Benchmarks Game ! http://benchmarksgame.alioth.debian.org/ ! ! Translated from Mark C. Lewis nbody.java by Simon Geard ! Revised by Mike Garrahan ! minor changes for speed improvement by Gilbert Brietzke ! ! ifort -O2 -xHost -o nbody nbody.f90 program nbody implicit none integer, parameter :: dp=kind(1.d0) real(dp),parameter :: TSTEP=0.01d0, PI=3.141592653589793d0 real(dp),parameter :: SOLAR_MASS=4*PI*PI,DAYS_PER_YEAR=365.24d0 integer ,parameter :: NB=5,NPAIR=NB*(NB-1)/2 real(dp) :: x(3,NB), v(3,NB), mass(NB), e integer :: nstep,i character(len=8) :: argv call get_command_argument(1, argv);read (argv,*) nstep call init(x,v,mass) e = energy(x,v,mass) write (*,'(f12.9)') e do i = 1, nstep call advance(x,v,mass) end do e = energy(x,v,mass) write (*,'(f12.9)') e contains subroutine advance(x,v,mass) real(dp), intent(inout) :: x(3,NB),v(3,NB) real(dp), intent(in) :: mass(NB) real(dp) :: r(3,NPAIR),rmag(3),mag(NPAIR) integer :: i,j,k k = 1 do i = 1, NB - 1 do j = i + 1, NB r(:,k) = x(:,i) - x(:,j) k = k + 1 end do end do mag = TSTEP/norm2(r,dim=1)**3 k = 1 do i = 1, NB - 1 do j = i + 1, NB v(:,i) = v(:,i) - mass(j)*mag(k)*r(:,k) v(:,j) = v(:,j) + mass(i)*mag(k)*r(:,k) k = k + 1 end do end do x = x + TSTEP*v end subroutine advance function energy(x,v,mass) real(dp), intent(in) :: x(3,NB),v(3,NB),mass(NB) real(dp) :: energy,pe integer :: i,j energy = 0.5d0*dot_product(mass,sum(v**2,dim=1)) do i = 1, NB - 1 do j = i + 1, NB pe = pe - mass(i)*mass(j)/norm2(x(:,i) - x(:,j)) end do end do energy = energy + pe end function energy subroutine init(x,v,mass) real(dp),intent(out)::x(3,NB),v(3,NB),mass(NB) real(dp),dimension(3,NB),parameter :: xi=reshape([0.d0,0.d0,0.d0,& &4.84143144246472090d+00,-1.16032004402742839d+00,-1.03622044471123109d-01,& &8.34336671824457987d+00, 4.12479856412430479d+00,-4.03523417114321381d-01,& &1.28943695621391310d+01,-1.51111514016986312d+01,-2.23307578892655734d-01,& &1.53796971148509165d+01,-2.59193146099879641d+01, 1.79258772950371181d-01],& &[3,NB]) real(dp),dimension(3,NB),parameter:: vi=reshape([0.d0,0.d0,0.d0,& &1.66007664274403694d-03,7.69901118419740425d-03,-6.90460016972063023d-05,& &-2.76742510726862411d-03,4.99852801234917238d-03, 2.30417297573763929d-05,& &2.96460137564761618d-03,2.37847173959480950d-03,-2.96589568540237556d-05,& &2.68067772490389322d-03,1.62824170038242295d-03,-9.51592254519715870d-05],& &[3,NB]) real(dp),dimension(NB),parameter :: massi=[1.0d0,9.54791938424326609d-04,& &2.85885980666130812d-04, 4.36624404335156298d-05, 5.15138902046611451d-05] x = xi v = vi*DAYS_PER_YEAR mass = massi * SOLAR_MASS v(:,1) = v(:,1) - matmul(v, mass)/mass(1) end subroutine init end program nbody
make, command-line, and program output logs
Tue, 15 Jan 2013 07:42:32 GMT MAKE: /usr/local/src/intel/bin/ifort -O3 -fast nbody.ifc-4.f90 -o nbody.ifc-4.ifc_run ipo: remark #11001: performing single-file optimizations ipo: remark #11006: generating object file /tmp/ipo_ifortdk8rbX.o rm nbody.ifc-4.f90 0.52s to complete and log all make actions COMMAND LINE: ./nbody.ifc-4.ifc_run 50000000 PROGRAM OUTPUT: -0.169075164 -0.169059907