Fastest cpu secs Swift versus C gcc 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 cpu seconds, less gz source code. fannkuch-redux source mem gz cpu C gcc #6 1,044 1576 8.26 C gcc #4 964 1183 13.89 C gcc #5 1,072 910 29.38 Swift #3 6,644 1097 31.59 Swift 6,456 451 35.27 C gcc #3 1,016 567 42.18 C gcc 988 508 43.27 C gcc #2 1,140 1557 45.01 n-body source mem gz cpu C gcc #9 992 1633 2.12 C gcc #8 8 1391 4.10 C gcc #4 1,304 1490 4.44 Swift #4 14,076 1355 5.28 Swift #5 10,800 1365 5.29 Swift #7 14,024 1326 5.33 Swift #8 14,028 1681 5.70 C gcc #5 1,020 1429 6.10 Swift #6 6,356 1194 6.11 C gcc #7 1,300 1244 6.79 C gcc #2 1,264 1263 7.19 C gcc #6 1,304 1180 7.21 C gcc #3 1,304 1208 7.23 C gcc 1,264 1173 7.55 Swift #3 6,452 1204 8.11 Swift #2 6,420 1192 8.68 Swift #9 14,032 1526 292.55 spectral-norm source mem gz cpu C gcc #6 1,068 1197 1.57 C gcc #5 1,344 569 2.85 C gcc #4 1,352 1139 2.85 Swift 12,872 438 5.32 C gcc 1,248 383 5.38 C gcc #3 1,348 463 5.68 Swift #3 6,876 601 5.68 mandelbrot source mem gz cpu C gcc #6 31,244 1135 5.12 Swift #7 41,804 1140 5.29 Swift #6 44,504 1141 5.43 C gcc #8 33,068 782 6.29 C gcc #4 32,704 799 13.81 C gcc #7 33,108 994 13.87 C gcc 29,692 822 13.91 C gcc #3 29,840 763 13.99 C gcc #9 32,904 694 16.03 C gcc #2 1,040 400 25.30 Swift 6,484 394 26.22 Swift #5 41,620 659 26.91 Swift #3 Bad Output pidigits source mem gz cpu C gcc 2,648 452 0.73 C gcc #2 2,920 416 0.74 Swift #2 8,132 600 0.74 regex-redux source mem gz cpu C gcc #5 152,220 1397 2.02 C gcc #2 103,084 1115 3.23 C gcc #4 152,056 1230 3.24 C gcc #3 103,540 1266 3.31 Swift #2 682,836 671 43.47 Swift 879,156 715 44.12 Swift #4 1,061,888 745 45.38 fasta source mem gz cpu C gcc #9 1,256 1463 0.78 C gcc #5 1,052 1281 1.30 C gcc #8 1,044 1293 2.74 C gcc #6 2,140 1930 2.76 C gcc #4 1,020 1240 3.06 Swift #2 7,440 1945 3.17 C gcc #2 2,860 2268 3.25 C gcc #7 2,864 2011 3.28 C gcc 1,016 1206 3.67 C gcc #3 972 819 4.49 Swift 6,908 1526 4.52 Swift #3 26,916 2090 4.64 k-nucleotide source mem gz cpu C gcc 130,156 1506 12.31 Swift #2 257,052 1367 52.46 Swift Make Error reverse-complement source mem gz cpu C gcc #7 499,132 1965 0.57 C gcc #8 499,184 1627 0.77 C gcc #6 688,416 820 1.27 C gcc #5 994,088 647 1.42 C gcc #2 994,152 750 1.45 Swift 794,484 1286 2.26 C gcc #4 500,416 709 3.49 binary-trees source mem gz cpu C gcc #2 168,384 809 4.32 C gcc #3 134,068 836 4.71 C gcc 263,664 654 22.16 C gcc #5 351,304 908 32.02 Swift #5 733,388 806 41.37 Swift #3 700,092 862 43.45 Swift #2 699,876 816 44.09 Swift 733,908 714 59.11 Swift #4 700,512 765 60.93 Swift #9 Make Error Swift Swift version 5.7-dev (LLVM a177fc627109410, Swift 31967c6df177cce) C gcc 11.2.0-19ubuntu1 all Swift programs & measurements all C gcc programs & measurements