Classic Fortran versus Classic C fastest performance Always look at the source code. If the fastest programs are hand-written vector instructions, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code. fannkuch-redux source secs mem gz cpu secs Classic C #6 2.22 11,248 1576 8.79 Classic C #4 15.53 11,244 1183 15.53 Classic C #3 33.74 11,236 567 33.74 Classic C #5 9.05 11,160 910 35.85 Classic Fortran 38.62 10,908 599 38.62 Classic C #2 10.22 11,236 1557 39.51 Classic C 40.46 11,224 508 40.46 Classic Fortran #3 10.26 11,160 1158 40.95 n-body source secs mem gz cpu secs Classic C #9 2.82 11,392 1633 2.82 Classic Fortran #6 4.20 10,960 1524 4.20 Classic Fortran #2 5.37 10,960 1500 5.36 Classic Fortran 5.48 10,960 1393 5.48 Classic C #7 5.68 11,392 1244 5.68 Classic C 5.73 11,392 1173 5.73 Classic Fortran #5 6.04 10,960 1664 6.03 Classic Fortran #4 6.15 10,960 1179 6.15 Classic C #3 6.31 11,392 1208 6.31 Classic Fortran #3 6.32 10,960 1305 6.32 Classic C #2 6.36 11,392 1263 6.36 Classic C #6 6.45 11,392 1180 6.45 Classic C #4 7.04 11,392 1490 7.03 Classic C #8 Make Error Classic C #5 Make Error spectral-norm source secs mem gz cpu secs Classic C #6 0.53 11,392 1197 2.11 Classic Fortran #2 2.66 10,984 513 2.66 Classic C 2.67 11,392 383 2.66 Classic C #5 0.71 11,392 569 2.84 Classic Fortran #3 0.71 10,984 638 2.84 Classic C #7 0.71 11,392 900 2.84 Classic C #4 0.72 11,392 1139 2.87 Classic C #3 0.72 11,392 463 2.88 Classic C #8 Failed mandelbrot source secs mem gz cpu secs Classic Fortran #8 1.41 75,272 957 5.58 Classic C #8 1.53 34,980 782 6.10 Classic Fortran #6 3.21 75,684 661 10.82 Classic C #9 3.63 34,364 694 14.49 Classic C #2 24.82 11,180 406 24.82 Classic Fortran #4 10.21 75,376 618 26.51 Classic Fortran #5 45.35 43,632 520 45.35 Classic C Make Error Classic C #6 Make Error Classic C #7 Make Error Classic C #3 Make Error Classic C #4 Make Error pidigits source secs mem gz cpu secs Classic C #2 0.82 11,392 416 0.82 Classic Fortran #4 0.88 10,956 981 0.88 Classic C 0.88 11,392 452 0.88 regex-redux source secs mem gz cpu secs Classic C #5 0.85 154,660 1397 2.82 Classic Fortran 0.92 175,800 2225 3.01 Classic C #2 3.22 103,780 1115 3.22 Classic C #4 0.99 154,472 1230 3.87 Classic C #3 1.85 106,328 1266 4.41 fasta source secs mem gz cpu secs Classic C #9 1.00 11,392 1463 1.00 Classic C #5 1.89 11,392 1281 1.89 Classic Fortran #4 2.07 10,936 1351 2.07 Classic C #4 3.19 11,248 1240 3.19 Classic C #6 1.19 11,284 1930 3.48 Classic C 4.02 11,288 1206 4.01 Classic C #2 1.06 11,392 2268 4.20 Classic C #7 1.09 11,392 2011 4.24 Classic C #3 4.82 11,392 819 4.82 Classic C #8 5.01 11,392 1293 5.01 Classic Fortran #3 6.73 10,940 1215 6.72 Classic Fortran 7.06 10,940 1190 7.06 k-nucleotide source secs mem gz cpu secs Classic C 4.91 129,316 1506 9.21 Classic Fortran Make Error reverse-complement source secs mem gz cpu secs Classic C #7 0.43 499,880 1895 0.63 Classic C #8 0.46 499,856 1543 0.75 Classic C #5 1.52 994,320 647 1.52 Classic C #2 1.20 994,360 750 1.73 Classic Fortran 4.06 986,344 1019 4.06 Classic C #6 1.11 799,692 820 4.44 Classic C #4 4.69 500,924 709 4.69 Classic Fortran #2 41.15 769,664 772 41.14 binary-trees source secs mem gz cpu secs Classic C #2 1.59 170,172 809 5.10 Classic C #3 1.85 134,956 836 5.84 Classic Fortran #2 2.16 136,456 1148 6.76 Classic C 17.76 264,064 654 17.75 Classic C #5 7.98 351,632 908 28.65 Classic Fortran 31.75 525,968 773 31.75 Classic Fortran Fortran Intel(R) 64 Classic 2021.8.0 20221119 Classic C deprecated C Intel(R) 64 Classic 2021.8.0 20221119 all Classic Fortran programs & measurements all Classic C programs & measurements