## Performance: Timing the speed of SPRNG Libraries

On building the SPRNG library, executables will be created to time each generator provided. A shell script called

timesprngis provided that will run each of these timing executables. Enter the following command in the same directory where the SPRNG libraries reside in order to determine the speeds of the generators on your machine:

timesprngThe output will give the time taken to generate a million random numbers and also the number of random numbers generated per second, in millions (MRS). These results are based on the timings in C programs. FORTRAN timings are also given for millions of random numbers generated per second.

We give below a table of timing results on a few parallel platforms, in Millions of Random Numbers per Second for the integer and double precision numbers generated:

Time SPRNGCRAY T3E HP/CONVEX Exemplar IBM SP2 SGI-CRAY Origin 2000 SGI Power Challenge Clock Speed MHz 300 180 135 195 195 drand48()

(for comparison)2.6 0.32 1.4 1.8 1.8 C LCG48

Integer14.5 7.7 4.4 10.3 10.2 C LCG48

Double Precision6.3 5.9 5.0 8.7 8.3 FORTRAN LCG48

Integer12.8 7.7 5.3 10.3 10.2 FORTRAN LCG48

Double Precision6.1 6.2 3.3 8.5 8.5 C LFG

Integer5.5 6.7 4.0 6.1 5.8 C LFG

Double Precision3.2 3.2 3.2 3.8 3.8 FORTRAN LFG

Integer5.4 6.3 4.1 5.2 5.3 FORTRAN LFG

Double Precision3.3 2.9 3.2 3.6 3.8 C LCG64

Integer16.6 10.0 5.6 11.5 11.5 C LCG64

Double Precision6.5 6.7 4.0 7.8 7.8 FORTRAN LCG64

Integer14.5 7.7 5.0 10.8 10.8 FORTRAN LCG64

Double Precision6.3 6.3 3.6 7.8 7.8 C CMRG

Integer8.6 5.6 1.9 4.6 4.7 C CMRG

Double Precision4.8 4.8 1.8 3.6 4.3 FORTRAN CMRG

Integer8.4 5.0 1.9 4.2 4.5 FORTRAN CMRG

Double Precision4.7 4.8 1.7 3.6 3.5 C MLFG

Integer5.6 5.3 4.2 8.3 8.3 C MLFG

Double Precision5.0 5.3 3.1 6.0 6.1 FORTRAN MLFG

Integer5.9 3.3 3.8 7.6 8.2 FORTRAN MLFG

Double Precision3.1 2.8 3.2 5.6 6.0 C PMLCG

Integer7.5 0.7 2.2 2.5 2.4 C PMLCG

Double Precision4.2 0.7 1.8 2.3 2.3 FORTRAN PMLCG

Integer7.2 0.61 1.9 2.5 2.5 FORTRAN PMLCG

Double Precision4.1 0.58 1.9 2.4 2.5