Swift versus Java 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 Swift 33.85 19,660 457 33.85 Swift #3 8.58 19,660 1103 33.96 Java #3 40.76 42,844 1264 40.83 Java 10.98 42,812 1289 43.36 Java #2 44.03 40,916 520 44.09 n-body source secs mem gz cpu secs Swift #4 5.49 19,680 1361 5.49 Swift #5 5.51 19,812 1372 5.51 Swift #7 5.52 19,684 1333 5.52 Swift #6 5.97 19,680 1200 5.97 Swift #8 5.99 19,808 1688 5.99 Java #5 6.78 41,384 1435 6.82 Java #4 6.87 41,188 1495 6.91 Java #2 7.42 41,308 1430 7.46 Java #3 7.47 41,256 1436 7.51 Java 7.85 41,512 1437 7.89 Swift #2 9.55 19,684 1198 9.55 Swift #3 202.89 19,680 1210 202.89 Swift #9 287.28 19,684 1532 287.27 spectral-norm source secs mem gz cpu secs Swift 5.32 19,684 444 5.32 Swift #3 1.43 19,684 607 5.69 Java #3 1.66 42,924 762 6.21 Java 7.07 42,268 521 7.13 Java #2 2.40 42,164 956 9.25 mandelbrot source secs mem gz cpu secs Swift #7 1.34 47,104 1147 5.30 Swift #6 1.45 50,176 1147 5.73 Java #4 4.45 104,488 667 16.20 Java #2 4.13 83,152 802 16.22 Java #6 4.28 83,056 808 16.84 Java 25.70 41,388 671 25.76 Swift 26.40 19,680 400 26.40 Swift #5 7.21 43,520 665 26.95 Java #3 7.86 83,424 910 30.96 Swift #3 Bad Output pidigits source secs mem gz cpu secs Swift #2 0.88 19,684 606 0.88 Java #3 0.93 40,860 770 0.96 Java #2 1.34 44,524 944 1.42 Java 7.61 486,236 807 8.69 regex-redux source secs mem gz cpu secs Java 8.38 666,804 875 16.42 Java #3 5.17 671,372 935 17.04 Java #6 5.57 1,234,928 746 17.17 Swift #2 41.76 684,640 678 41.75 Swift 24.13 889,972 721 42.70 Swift #4 20.41 1,060,208 751 44.32 fasta source secs mem gz cpu secs Java #4 3.15 42,784 1528 3.26 Java #6 1.18 48,408 2549 3.71 Java #5 1.24 48,752 2478 3.81 Swift #2 2.18 19,680 1952 3.83 Java #2 4.35 47,184 1259 4.50 Swift 5.15 19,676 1533 5.15 Swift #3 2.14 29,584 2097 5.26 k-nucleotide source secs mem gz cpu secs Java 5.01 368,104 1821 16.33 Java #6 7.18 365,592 1614 25.01 Java #3 7.30 365,348 1642 25.39 Java #4 34.43 195,584 1887 34.79 Java #5 16.05 219,872 2225 38.17 Swift #2 14.51 259,048 1373 55.29 Swift Make Error reverse-complement source secs mem gz cpu secs Swift 1.88 796,840 1293 2.30 Java #6 3.33 2,031,460 760 3.96 Java #5 4.73 1,096,344 1115 4.86 Java #4 5.57 1,889,928 656 5.68 Java #7 23.06 1,036,296 1654 6.31 Java #3 Bad Output Java #8 Bad Output binary-trees source secs mem gz cpu secs Java #4 4.50 2,081,744 846 5.22 Java #3 4.80 2,076,860 546 5.59 Java #6 4.84 2,097,072 535 5.60 Java #2 4.93 2,067,656 558 5.67 Java #7 2.57 1,728,452 841 8.00 Swift #5 13.79 736,000 813 40.99 Swift #3 13.33 705,408 868 43.00 Swift #2 13.28 705,280 822 43.28 Swift 20.15 735,488 720 59.68 Swift #4 19.49 705,536 772 62.34 Swift #9 Make Error Swift Swift version 5.10 (swift-5.10-RELEASE) Java java 22 2024-03-19 Java HotSpot(TM) 64-Bit Server VM (build 22+36-2370, mixed mode, sharing) all Swift programs & measurements all Java programs & measurements