COMPUTE_PI FORTRAN77/OpenMP version Estimate PI by summing a series. The number of processors = 8 The number of threads = 1 R8_TEST: Estimate the value of PI, using double precision arithmetic. N = number of terms computed and added; MODE = SEQ for sequential code; MODE = OMP for Open MP enabled code; (performance depends on if Open MP is used, and how many processes are availablec) ESTIMATE = the computed estimate of PI; ERROR = ( the computed estimate - PI ); TIME = elapsed wall clock time; You can't increase N forever, because: A) ROUNDOFF starts to be a problem, and B) maximum integer size is a problem. N Mode Estimate Error Time 1 SEQ 3.2000000000 0.584073E-01 0.00000 1 OMP 3.2000000000 0.584073E-01 0.119209E-04 10 SEQ 3.1424259850 0.833331E-03 0.00000 10 OMP 3.1424259850 0.833331E-03 0.190735E-05 100 SEQ 3.1416009869 0.833333E-05 0.190735E-05 100 OMP 3.1416009869 0.833333E-05 0.214577E-05 1000 SEQ 3.1415927369 0.833333E-07 0.159740E-04 1000 OMP 3.1415927369 0.833333E-07 0.169277E-04 10000 SEQ 3.1415926544 0.833341E-09 0.159979E-03 10000 OMP 3.1415926544 0.833341E-09 0.164986E-03 100000 SEQ 3.1415926536 0.836842E-11 0.161910E-02 100000 OMP 3.1415926536 0.836842E-11 0.163579E-02 1000000 SEQ 3.1415926536 0.284217E-13 0.161788E-01 1000000 OMP 3.1415926536 0.284217E-13 0.166271E-01 10000000 SEQ 3.1415926536 0.621725E-13 0.161056 10000000 OMP 3.1415926536 0.621725E-13 0.164422 100000000 SEQ 3.1415926536 0.633271E-12 1.61104 100000000 OMP 3.1415926536 0.633271E-12 1.64432 1000000000 SEQ 3.1415926536 0.177636E-12 16.1013 1000000000 OMP 3.1415926536 0.177636E-12 16.4560 COMPUTE_PI Normal end of execution. COMPUTE_PI FORTRAN77/OpenMP version Estimate PI by summing a series. The number of processors = 8 The number of threads = 2 R8_TEST: Estimate the value of PI, using double precision arithmetic. N = number of terms computed and added; MODE = SEQ for sequential code; MODE = OMP for Open MP enabled code; (performance depends on if Open MP is used, and how many processes are availablec) ESTIMATE = the computed estimate of PI; ERROR = ( the computed estimate - PI ); TIME = elapsed wall clock time; You can't increase N forever, because: A) ROUNDOFF starts to be a problem, and B) maximum integer size is a problem. N Mode Estimate Error Time 1 SEQ 3.2000000000 0.584073E-01 0.00000 1 OMP 3.2000000000 0.584073E-01 0.929832E-04 10 SEQ 3.1424259850 0.833331E-03 0.00000 10 OMP 3.1424259850 0.833331E-03 0.228882E-04 100 SEQ 3.1416009869 0.833333E-05 0.190735E-05 100 OMP 3.1416009869 0.833333E-05 0.169277E-04 1000 SEQ 3.1415927369 0.833333E-07 0.169277E-04 1000 OMP 3.1415927369 0.833333E-07 0.219345E-04 10000 SEQ 3.1415926544 0.833341E-09 0.167847E-03 10000 OMP 3.1415926544 0.833336E-09 0.979900E-04 100000 SEQ 3.1415926536 0.836842E-11 0.167513E-02 100000 OMP 3.1415926536 0.835332E-11 0.868082E-03 1000000 SEQ 3.1415926536 0.284217E-13 0.164270E-01 1000000 OMP 3.1415926536 0.106137E-12 0.876284E-02 10000000 SEQ 3.1415926536 0.621725E-13 0.161256 10000000 OMP 3.1415926536 0.129674E-12 0.857251E-01 100000000 SEQ 3.1415926536 0.633271E-12 1.61163 100000000 OMP 3.1415926536 0.116351E-12 0.855946 1000000000 SEQ 3.1415926536 0.177636E-12 16.1657 1000000000 OMP 3.1415926536 0.107914E-12 8.56312 COMPUTE_PI Normal end of execution. COMPUTE_PI FORTRAN77/OpenMP version Estimate PI by summing a series. The number of processors = 8 The number of threads = 4 R8_TEST: Estimate the value of PI, using double precision arithmetic. N = number of terms computed and added; MODE = SEQ for sequential code; MODE = OMP for Open MP enabled code; (performance depends on if Open MP is used, and how many processes are availablec) ESTIMATE = the computed estimate of PI; ERROR = ( the computed estimate - PI ); TIME = elapsed wall clock time; You can't increase N forever, because: A) ROUNDOFF starts to be a problem, and B) maximum integer size is a problem. N Mode Estimate Error Time 1 SEQ 3.2000000000 0.584073E-01 0.00000 1 OMP 3.2000000000 0.584073E-01 0.275850E-03 10 SEQ 3.1424259850 0.833331E-03 0.953674E-06 10 OMP 3.1424259850 0.833331E-03 0.410080E-04 100 SEQ 3.1416009869 0.833333E-05 0.214577E-05 100 OMP 3.1416009869 0.833333E-05 0.209808E-04 1000 SEQ 3.1415927369 0.833333E-07 0.171661E-04 1000 OMP 3.1415927369 0.833333E-07 0.219345E-04 10000 SEQ 3.1415926544 0.833341E-09 0.168085E-03 10000 OMP 3.1415926544 0.833331E-09 0.600815E-04 100000 SEQ 3.1415926536 0.836842E-11 0.167489E-02 100000 OMP 3.1415926536 0.833333E-11 0.450850E-03 1000000 SEQ 3.1415926536 0.284217E-13 0.166011E-01 1000000 OMP 3.1415926536 0.821565E-13 0.451803E-02 10000000 SEQ 3.1415926536 0.621725E-13 0.162830 10000000 OMP 3.1415926536 0.123457E-12 0.436821E-01 100000000 SEQ 3.1415926536 0.633271E-12 1.62519 100000000 OMP 3.1415926536 0.110578E-12 0.433904 1000000000 SEQ 3.1415926536 0.177636E-12 16.1796 1000000000 OMP 3.1415926536 0.275335E-13 4.31254 COMPUTE_PI Normal end of execution.