Java versus C++ g++ fastest programs Always look at the source code. These are only the fastest programs. Do some of them use manually vectorized SIMD? Look at the other programs. They may seem more-like a fair comparison to you. pidigits source secs mem gz busy cpu load Java 0.93 36,088 764 0.97 4% 0% 1% 99% C++ g++ 0.66 5,152 986 2.63 100% 100% 100% 100% fasta source secs mem gz busy cpu load Java 1.19 44,740 2543 3.50 75% 63% 87% 70% C++ g++ 0.77 2,504 2751 1.52 64% 0% 99% 37% spectral-norm source secs mem gz busy cpu load Java 1.58 39,408 756 5.97 94% 94% 96% 94% C++ g++ 0.72 1,192 1044 2.85 99% 99% 100% 100% k-nucleotide source secs mem gz busy cpu load Java 4.85 354,288 1812 15.92 80% 85% 87% 76% C++ g++ 1.93 156,548 1631 5.88 69% 93% 69% 75% binary-trees source secs mem gz busy cpu load Java 2.48 1,725,776 835 7.86 74% 75% 97% 72% C++ g++ 0.94 176,428 1122 3.39 86% 88% 100% 85% reverse-complement source secs mem gz busy cpu load Java 1.53 687,864 2183 3.50 80% 46% 57% 46% C++ g++ 0.52 1,788 1853 0.52 0% 98% 0% 2% fannkuch-redux source secs mem gz busy cpu load Java 10.38 35,388 1282 40.84 99% 99% 98% 97% C++ g++ 3.29 1,892 1528 13.06 100% 100% 100% 97% n-body source secs mem gz busy cpu load Java 6.77 35,432 1489 6.82 100% 1% 0% 0% C++ g++ 2.12 764 1927 2.17 0% 2% 100% 0% regex-redux source secs mem gz busy cpu load Java 5.31 793,572 929 17.50 79% 78% 83% 89% C++ g++ 1.10 203,924 1315 3.43 63% 77% 71% 100% mandelbrot source secs mem gz busy cpu load Java 4.12 70,952 796 16.22 98% 98% 98% 99% C++ g++ 0.84 34,780 3542 3.27 99% 98% 98% 96% Java openjdk 17 2021-09-14 OpenJDK Runtime Environment (build 17+35-2724) OpenJDK 64-Bit Server VM (build 17+35-2724, mixed mode, sharing) C++ g++ g++ (Ubuntu 10.3.0-1ubuntu1) 10.3.0 all Java programs & measurements all C++ g++ programs & measurements