Fastest cpu secs Swift versus Java 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 Swift #3 6,644 1097 31.59 Swift 6,456 451 35.27 Java #3 35,324 1257 41.17 Java 35,824 1282 41.74 Java #2 34,244 514 44.98 n-body source mem gz cpu 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 Swift #6 6,356 1194 6.11 Java #5 34,252 1429 6.79 Java #4 34,076 1489 6.79 Java #3 34,612 1430 7.50 Java #2 34,704 1424 7.50 Java 37,380 1430 7.83 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 Swift 12,872 438 5.32 Swift #3 6,876 601 5.68 Java #3 38,428 756 5.94 Java 37,288 514 9.76 Java #2 37,368 950 10.07 mandelbrot source mem gz cpu Swift #7 41,804 1140 5.29 Swift #6 44,504 1141 5.43 Java #4 66,304 660 16.16 Java #2 68,860 796 16.21 Java #6 67,432 802 16.92 Swift 6,484 394 26.22 Swift #5 41,620 659 26.91 Java 34,252 665 27.75 Java #3 69,200 903 29.18 Swift #3 Bad Output pidigits source mem gz cpu Swift #2 8,132 600 0.74 Java #3 35,700 764 0.82 Java #2 38,328 938 1.53 Java 513,728 800 8.94 regex-redux source mem gz cpu Java 924,116 868 17.12 Java #6 728,332 740 17.16 Java #3 741,028 929 17.34 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 Swift #2 7,440 1945 3.17 Java #4 36,800 1524 3.41 Java #6 42,416 2543 3.52 Java #5 42,532 2473 4.14 Java #2 36,812 1257 4.46 Swift 6,908 1526 4.52 Swift #3 26,916 2090 4.64 k-nucleotide source mem gz cpu Java 349,544 1812 16.17 Java #6 343,684 1607 25.67 Java #3 344,652 1635 25.73 Java #4 199,824 1882 37.48 Java #5 210,368 2219 43.27 Swift #2 257,052 1367 52.46 Swift Make Error reverse-complement source mem gz cpu Swift 794,484 1286 2.26 Java #8 665,804 2183 3.49 Java #6 2,024,016 752 4.15 Java #5 1,088,392 1108 4.92 Java #3 1,170,232 1722 5.09 Java #4 1,881,900 651 5.41 Java #7 1,030,892 1647 23.16 binary-trees source mem gz cpu Java #3 2,106,820 540 5.19 Java #6 2,093,916 529 5.35 Java #4 2,079,388 840 5.44 Java #2 1,877,464 552 5.45 Java #7 2,460,388 835 7.73 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) Java openjdk 18 2022-03-22 OpenJDK Runtime Environment (build 18+36-2087) OpenJDK 64-Bit Server VM (build 18+36-2087, mixed mode, sharing) all Swift programs & measurements all Java programs & measurements