Rust versus C clang 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 clang #6 2.05 11,236 1576 8.13 C clang #4 13.11 11,248 1183 13.11 Rust #6 3.51 11,036 1253 13.93 Rust #4 7.21 10,932 1020 28.34 Rust #5 7.77 10,932 1016 30.49 C clang #5 8.24 11,160 910 32.64 C clang #2 8.82 11,208 1557 34.58 C clang #3 36.31 11,236 567 36.31 C clang 38.34 11,208 508 38.32 Rust #2 17.99 11,036 1191 70.95 n-body source secs mem gz cpu secs C clang #9 2.21 11,392 1633 2.21 Rust #9 2.81 11,068 1874 2.81 Rust #7 3.27 11,068 1753 3.27 Rust #6 3.92 11,068 1790 3.92 C clang #4 4.76 11,392 1490 4.76 C clang #5 5.62 11,392 1429 5.62 Rust #3 5.63 11,068 1540 5.63 C clang #8 5.63 11,392 1391 5.63 Rust 5.63 11,068 1480 5.63 C clang #6 5.75 11,392 1180 5.75 C clang #2 5.87 11,392 1263 5.87 Rust #2 5.98 11,068 1805 5.98 C clang 5.98 11,392 1173 5.98 Rust #8 6.01 11,068 1767 6.01 Rust #5 6.12 11,068 2220 6.11 Rust #4 6.20 11,068 1803 6.20 C clang #3 6.33 11,392 1208 6.33 C clang #7 6.92 11,392 1244 6.92 spectral-norm source secs mem gz cpu secs C clang #6 0.39 11,392 1197 1.55 C clang #5 0.71 11,392 569 2.84 Rust #6 0.71 11,124 1126 2.84 Rust #7 0.72 11,128 932 2.84 Rust #5 0.72 11,124 1055 2.84 Rust #4 0.72 11,124 817 2.84 Rust #2 0.72 11,124 1110 2.85 Rust 0.72 11,124 1254 2.85 C clang #4 0.73 11,392 1139 2.88 C clang #8 0.76 11,392 935 3.01 Rust #3 0.78 11,124 1053 3.07 C clang 5.31 11,392 383 5.31 C clang #3 1.42 11,392 463 5.67 C clang #7 1.83 11,392 900 7.08 mandelbrot source secs mem gz cpu secs Rust #4 1.01 32,380 1295 3.99 Rust #6 1.06 34,120 1332 4.18 Rust #5 1.12 33,868 719 4.41 Rust #3 1.15 13,452 1007 4.58 C clang #9 1.28 33,932 694 5.11 Rust #7 1.42 32,124 757 5.64 Rust #8 1.42 32,176 763 5.64 C clang #8 1.53 34,548 782 6.09 Rust 2.05 38,724 868 8.09 C clang #4 3.47 33,792 799 13.84 C clang 3.48 32,888 822 13.90 C clang #7 3.54 34,040 994 14.08 C clang #3 3.55 33,044 763 14.16 C clang #2 25.44 11,232 406 25.44 C clang #6 Make Error pidigits source secs mem gz cpu secs Rust #4 0.71 11,068 799 0.71 C clang #2 0.81 11,392 416 0.81 C clang 0.88 11,392 452 0.88 Rust #2 0.88 11,068 1306 0.88 Rust #3 0.88 11,068 1366 0.88 Rust 0.89 11,068 1420 0.88 regex-redux source secs mem gz cpu secs Rust #6 1.34 152,724 986 1.80 Rust #5 1.40 204,604 771 1.82 Rust #4 1.43 204,656 765 1.85 Rust 1.46 153,312 804 1.87 Rust #3 1.42 205,228 719 1.88 Rust #2 1.50 153,320 701 1.90 Rust #7 0.78 149,524 2458 1.99 C clang #5 0.81 154,176 1397 2.78 C clang #2 3.21 103,260 1115 3.21 C clang #4 0.94 154,012 1230 3.68 C clang #3 1.75 105,720 1266 4.32 fasta source secs mem gz cpu secs C clang #9 0.78 11,392 1463 0.78 C clang #5 1.22 11,392 1281 1.22 Rust #7 0.76 11,068 2529 1.52 Rust #3 2.00 11,036 1233 2.00 C clang #8 2.45 11,392 1293 2.45 C clang #4 2.95 11,392 1240 2.95 C clang #6 1.01 11,288 1930 2.95 Rust #5 0.90 11,060 1961 3.08 Rust #2 0.90 11,068 1906 3.16 C clang #2 0.82 11,288 2268 3.26 C clang #7 0.84 11,392 2011 3.26 Rust #4 3.46 123,660 939 3.46 Rust #6 3.50 123,660 955 3.50 Rust #8 0.92 11,068 1946 3.50 C clang 3.72 11,392 1206 3.72 Rust 4.52 11,036 1237 4.52 C clang #3 4.56 11,260 819 4.56 k-nucleotide source secs mem gz cpu secs Rust #7 2.88 133,236 1578 9.14 Rust #8 3.56 137,632 1543 10.34 Rust #6 2.88 158,788 1691 10.48 Rust #5 4.08 137,648 1739 11.99 C clang 5.97 128,860 1506 12.47 Rust #2 6.30 137,548 1347 16.69 Rust #9 6.54 136,008 1841 17.81 Rust #4 6.95 136,744 1749 18.88 Rust 21.93 155,840 1078 65.94 reverse-complement source secs mem gz cpu secs C clang #7 0.42 499,204 1895 0.59 C clang #8 0.46 499,624 1543 0.70 Rust 0.47 498,844 3040 0.77 Rust #2 0.80 995,004 1330 1.45 Rust #3 0.81 995,004 1097 1.50 C clang #2 1.10 993,892 750 1.62 C clang #5 2.01 993,848 647 2.01 C clang #4 3.73 500,380 709 3.73 C clang #6 0.95 726,524 820 3.79 binary-trees source secs mem gz cpu secs Rust #5 1.08 198,984 765 3.82 Rust #2 1.19 200,532 721 4.27 Rust #4 1.28 198,772 756 4.62 Rust #3 1.36 198,464 754 4.93 C clang #2 1.67 169,692 809 5.44 C clang #3 1.77 134,200 836 5.59 Rust 2.10 132,828 751 7.39 C clang 17.82 264,056 654 17.82 C clang #5 8.97 351,200 908 32.22 Rust 1.67.0 (fc594f156 2023-01-24) LLVM version: 15.0.6 C clang Ubuntu clang version 15.0.2-1 all Rust programs & measurements all C clang programs & measurements