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 | 0.20 | 0.22 | 520 | 1496 | 0% 5% 5% 96% |
| 5,000,000 | 2.01 | 2.01 | 520 | 1496 | 0% 0% 1% 100% |
| 50,000,000 | 20.05 | 20.06 | 520 | 1496 | 0% 0% 1% 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 #2 program source code
! The Computer Language Benchmarks Game ! http://benchmarksgame.alioth.debian.org/ ! ! contributed by Simon Geard, translated from Mark C. Williams nbody.java ! modified by Brian Taylor ! ! ifort -fast -o nbody nbody.f90 ! program nbody implicit none real*8, parameter :: tstep = 0.01d0 real*8, parameter :: PI = 3.141592653589793d0 real*8, parameter :: SOLAR_MASS = 4 * PI * PI real*8, parameter :: DAYS_PER_YEAR = 365.24d0 type body real*8 :: x, y, z, vx, vy, vz, mass end type body type(body), parameter :: jupiter = body( & 4.84143144246472090d0, -1.16032004402742839d0, & -1.03622044471123109d-01, 1.66007664274403694d-03 * DAYS_PER_YEAR, & 7.69901118419740425d-03 * DAYS_PER_YEAR, & -6.90460016972063023d-05 * DAYS_PER_YEAR, & 9.54791938424326609d-04 * SOLAR_MASS) type(body), parameter :: saturn = body( & 8.34336671824457987d+00, & 4.12479856412430479d+00, & -4.03523417114321381d-01, & -2.76742510726862411d-03 * DAYS_PER_YEAR, & 4.99852801234917238d-03 * DAYS_PER_YEAR, & 2.30417297573763929d-05 * DAYS_PER_YEAR, & 2.85885980666130812d-04 * SOLAR_MASS) type(body), parameter :: uranus = body( & 1.28943695621391310d+01, & -1.51111514016986312d+01, & -2.23307578892655734d-01, & 2.96460137564761618d-03 * DAYS_PER_YEAR, & 2.37847173959480950d-03 * DAYS_PER_YEAR, & -2.96589568540237556d-05 * DAYS_PER_YEAR, & 4.36624404335156298d-05 * SOLAR_MASS ) type(body), parameter :: neptune = body( & 1.53796971148509165d+01, & -2.59193146099879641d+01, & 1.79258772950371181d-01, & 2.68067772490389322d-03 * DAYS_PER_YEAR, & 1.62824170038242295d-03 * DAYS_PER_YEAR, & -9.51592254519715870d-05 * DAYS_PER_YEAR, & 5.15138902046611451d-05 * SOLAR_MASS) type(body), parameter :: sun = body(0.0d0, 0.0d0, 0.0d0, 0.0d0, 0.0d0, & 0.0d0, SOLAR_MASS) integer, parameter :: nb = 5 real*8, parameter :: mass(nb) = (/ sun%mass, jupiter%mass, saturn%mass, & uranus%mass, neptune%mass /) integer :: num, i character(len=8) :: argv real*8 :: e, x(3,nb), v(3,nb) x(:,1) = (/ sun%x, sun%y, sun%z /) x(:,2) = (/ jupiter%x, jupiter%y, jupiter%z /) x(:,3) = (/ saturn%x, saturn%y, saturn%z /) x(:,4) = (/ uranus%x, uranus%y, uranus%z /) x(:,5) = (/ neptune%x, neptune%y, neptune%z /) v(:,1) = (/ sun%vx, sun%vy, sun%vz /) v(:,2) = (/ jupiter%vx, jupiter%vy, jupiter%vz /) v(:,3) = (/ saturn%vx, saturn%vy, saturn%vz /) v(:,4) = (/ uranus%vx, uranus%vy, uranus%vz /) v(:,5) = (/ neptune%vx, neptune%vy, neptune%vz /) call getarg(1, argv) read (argv,*) num call offsetMomentum(1, v, mass) e = energy(x, v, mass) write (*,'(f12.9)') e do i = 1, num call advance(tstep, x, v, mass) end do e = energy(x, v, mass) write (*,'(f12.9)') e contains pure subroutine offsetMomentum(k, v, mass) integer, intent(in) :: k real*8, dimension(3,nb), intent(inout) :: v real*8, dimension(nb), intent(in) :: mass real*8 :: px, py, pz integer :: i px = 0.0d0 py = 0.0d0 pz = 0.0d0 do i = 1, nb px = px + v(1,i) * mass(i) py = py + v(2,i) * mass(i) pz = pz + v(3,i) * mass(i) end do v(1,k) = -px / SOLAR_MASS v(2,k) = -py / SOLAR_MASS v(3,k) = -pz / SOLAR_MASS end subroutine offsetMomentum pure subroutine advance(tstep, x, v, mass) real*8, intent(in) :: tstep real*8, dimension(3,nb), intent(inout) :: x, v real*8, dimension(nb), intent(in) :: mass real*8 :: dx, dy, dz, distance, mag integer :: i, j do i = 1, nb do j = i + 1, nb dx = x(1,i) - x(1,j) dy = x(2,i) - x(2,j) dz = x(3,i) - x(3,j) distance = sqrt(dx**2 + dy**2 + dz**2) mag = tstep / distance**3 v(1,i) = v(1,i) - dx * mass(j) * mag v(2,i) = v(2,i) - dy * mass(j) * mag v(3,i) = v(3,i) - dz * mass(j) * mag v(1,j) = v(1,j) + dx * mass(i) * mag v(2,j) = v(2,j) + dy * mass(i) * mag v(3,j) = v(3,j) + dz * mass(i) * mag end do end do do i = 1, nb x(1,i) = x(1,i) + tstep * v(1,i) x(2,i) = x(2,i) + tstep * v(2,i) x(3,i) = x(3,i) + tstep * v(3,i) end do end subroutine advance pure function energy(x, v, mass) real*8 :: energy real*8, dimension(3,nb), intent(in) :: x, v real*8, dimension(nb), intent(in) :: mass real*8 :: dx, dy, dz, distance integer :: i, j energy = 0.0d0 do i = 1, nb energy = energy + 0.5d0 * mass(i) * (v(1,i)**2 + v(2,i)**2 + v(3,i)**2) do j = i + 1, nb dx = x(1,i) - x(1,j) dy = x(2,i) - x(2,j) dz = x(3,i) - x(3,j) distance = sqrt(dx**2 + dy**2 + dz**2) energy = energy - (mass(i) * mass(j)) / distance; end do end do end function energy end program nbody
make, command-line, and program output logs
Tue, 15 Jan 2013 07:36:02 GMT MAKE: /usr/local/src/intel/bin/ifort -O3 -fast nbody.ifc-2.f90 -o nbody.ifc-2.ifc_run ipo: remark #11001: performing single-file optimizations ipo: remark #11006: generating object file /tmp/ipo_ifortAFToIk.o rm nbody.ifc-2.f90 0.45s to complete and log all make actions COMMAND LINE: ./nbody.ifc-2.ifc_run 50000000 PROGRAM OUTPUT: -0.169075164 -0.169059907