Python 3 versus Java fastest programs Always look at the source code. These are only the fastest programs. Look at the other programs. They may seem more-like a fair comparison to you. regex-redux source secs mem gz busy cpu load Python 3 1.36 112,052 1403 2.64 40% 88% 32% 33% Java 5.70 656,328 929 18.25 89% 76% 79% 75% pidigits source secs mem gz busy cpu load Python 3 1.28 12,336 567 1.30 1% 0% 1% 100% Java 0.79 35,568 764 0.84 99% 3% 3% 1% reverse-complement source secs mem gz busy cpu load Python 3 7.16 1,005,968 814 10.65 20% 53% 47% 29% Java 1.54 702,332 2183 3.55 78% 46% 49% 57% k-nucleotide source secs mem gz busy cpu load Python 3 46.37 239,472 1967 176.69 94% 95% 98% 94% Java 5.00 408,040 1812 16.36 74% 81% 86% 86% binary-trees source secs mem gz busy cpu load Python 3 49.35 278,628 589 174.26 95% 86% 86% 86% Java 2.50 2,487,096 835 7.90 88% 75% 75% 79% fasta source secs mem gz busy cpu load Python 3 39.10 846,628 1947 70.52 43% 8% 61% 69% Java 1.20 44,124 2543 3.61 79% 86% 69% 65% fannkuch-redux source secs mem gz busy cpu load Python 3 367.49 12,288 950 1,454.68 100% 98% 99% 98% Java 11.00 34,104 1282 43.42 99% 98% 98% 99% mandelbrot source secs mem gz busy cpu load Python 3 172.58 12,216 688 689.62 100% 100% 100% 100% Java 4.11 68,204 796 16.20 98% 99% 98% 99% spectral-norm source secs mem gz busy cpu load Python 3 118.40 22,912 407 470.86 99% 99% 99% 100% Java 1.68 38,348 950 6.43 96% 96% 96% 95% n-body source secs mem gz busy cpu load Python 3 586.17 8,012 1196 589.84 0% 0% 0% 100% Java 6.75 35,200 1489 6.83 0% 0% 100% 1% Python 3 Python 3.9.0 Java openjdk 15 2020-09-15 OpenJDK Runtime Environment (build 15+36-1562) OpenJDK 64-Bit Server VM (build 15+36-1562, mixed mode, sharing) all Python 3 programs & measurements all Java programs & measurements