Classic Fortran versus C++ g++ 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 C++ g++ #6 3.25 19,788 1535 12.89 C++ g++ #7 13.93 19,660 1156 13.93 C++ g++ #5 7.97 19,788 987 31.14 C++ g++ #3 36.80 19,660 600 36.80 C++ g++ #4 9.47 19,660 1445 37.11 C++ g++ #2 9.82 19,656 1446 38.58 Classic Fortran 38.73 19,724 608 38.73 Classic Fortran #3 10.14 19,724 1164 40.45 C++ g++ 10.59 19,660 1065 41.61 n-body source secs mem gz cpu secs C++ g++ #0 2.14 19,676 1933 2.14 C++ g++ #7 3.97 19,804 1815 3.97 C++ g++ #2 4.20 19,676 1884 4.19 Classic Fortran #6 4.21 19,856 1530 4.21 C++ g++ #3 5.30 19,804 1402 5.30 Classic Fortran #2 5.37 19,856 1507 5.37 C++ g++ #9 5.43 19,676 1536 5.43 Classic Fortran 5.43 19,728 1400 5.43 C++ g++ #4 5.44 19,804 1434 5.44 Classic Fortran #5 5.98 19,728 1669 5.98 C++ g++ #5 6.01 19,676 1544 6.00 Classic Fortran #4 6.18 19,728 1183 6.18 Classic Fortran #3 6.32 19,856 1311 6.32 C++ g++ 6.49 19,676 1666 6.49 C++ g++ #8 6.57 19,676 1524 6.57 C++ g++ #6 6.89 19,676 1674 6.89 spectral-norm source secs mem gz cpu secs Classic Fortran #2 2.66 19,736 520 2.66 C++ g++ #6 0.72 19,812 1050 2.84 Classic Fortran #3 0.72 19,736 644 2.87 C++ g++ #5 1.32 19,684 1050 5.25 C++ g++ 5.36 19,684 459 5.36 C++ g++ #8 1.52 19,684 1284 6.04 mandelbrot source secs mem gz cpu secs C++ g++ 0.89 34,944 1797 3.46 C++ g++ #4 0.89 35,200 3554 3.47 C++ g++ #6 0.98 35,072 1014 3.89 Classic Fortran #8 1.42 75,392 965 5.59 C++ g++ #0 2.35 35,328 2752 9.28 Classic Fortran #6 3.27 75,904 669 10.86 C++ g++ #8 4.79 35,072 749 13.12 C++ g++ #5 13.33 34,688 596 13.33 C++ g++ #9 3.50 35,200 732 13.49 C++ g++ #7 3.49 35,072 1023 13.90 C++ g++ #2 16.90 34,560 700 16.90 Classic Fortran #4 10.27 75,904 626 26.58 C++ g++ #3 27.26 19,804 421 27.25 Classic Fortran #5 45.21 43,648 528 45.21 pidigits source secs mem gz cpu secs C++ g++ #5 0.86 19,804 804 0.86 Classic Fortran #4 0.87 19,728 987 0.87 C++ g++ #4 0.88 19,804 521 0.88 regex-redux source secs mem gz cpu secs C++ g++ #6 1.15 276,276 2856 2.18 Classic Fortran 0.93 176,236 2229 3.04 C++ g++ #2 2.84 212,776 706 3.60 C++ g++ 3.62 212,180 662 3.62 C++ g++ #5 3.86 215,556 859 4.54 C++ g++ #3 12.41 217,580 859 17.91 C++ g++ #4 Make Error fasta source secs mem gz cpu secs C++ g++ #8 0.76 19,792 2758 1.51 C++ g++ #2 1.81 19,668 1129 1.81 C++ g++ 1.90 19,664 1064 1.90 Classic Fortran #4 2.05 19,728 1355 2.05 C++ g++ #3 2.62 19,664 1311 2.62 C++ g++ #4 3.32 19,664 1291 3.32 C++ g++ #6 1.05 19,668 2326 3.85 C++ g++ #5 1.05 19,668 2345 3.88 Classic Fortran #3 6.55 19,728 1217 6.55 Classic Fortran 6.85 19,728 1193 6.85 C++ g++ #7 Make Error k-nucleotide source secs mem gz cpu secs C++ g++ #2 1.97 156,504 1634 5.87 C++ g++ #3 4.19 165,592 1280 13.77 C++ g++ 6.90 757,080 1452 14.68 Classic Fortran Make Error reverse-complement source secs mem gz cpu secs C++ g++ #2 0.70 499,840 2099 0.70 Classic Fortran 4.15 986,304 1026 4.14 C++ g++ #6 3.20 1,517,660 1827 4.22 C++ g++ 6.56 980,060 599 6.56 C++ g++ #5 35.10 771,556 704 35.10 Classic Fortran #2 41.23 769,748 778 41.23 C++ g++ #3 Bad Output binary-trees source secs mem gz cpu secs C++ g++ #7 0.95 201,400 896 3.30 C++ g++ #5 1.14 200,660 891 3.98 C++ g++ #9 1.72 135,936 815 4.46 C++ g++ #6 1.88 266,112 851 4.47 C++ g++ #3 1.88 265,600 951 4.72 C++ g++ #8 2.18 265,984 826 5.11 Classic Fortran #2 2.26 136,704 1155 6.87 C++ g++ 2.65 2,040,792 760 9.07 C++ g++ #2 21.51 265,856 514 21.51 Classic Fortran 31.48 525,824 780 31.48 C++ g++ #4 Make Error Classic Fortran Fortran Compiler Classic 2021.11.1 20231117 C++ g++ Ubuntu 13.2.0-4ubuntu3 all Classic Fortran programs & measurements all C++ g++ programs & measurements