Java versus C++ g++ 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. pidigits source secs mem gz busy cpu load Java 0.94 35,604 764 0.99 1% 4% 3% 97% C++ g++ 0.89 4,236 513 0.89 0% 0% 100% 0% fannkuch-redux source secs mem gz busy cpu load Java 9.94 34,188 1282 39.21 99% 98% 99% 97% C++ g++ 7.92 1,700 980 30.88 100% 99% 98% 93% fasta source secs mem gz busy cpu load Java 1.28 44,172 2473 4.17 83% 78% 88% 76% C++ g++ 0.85 2,020 2711 3.13 92% 92% 92% 93% n-body source secs mem gz busy cpu load Java 6.76 35,156 1489 6.83 1% 0% 100% 1% C++ g++ 3.94 1,604 1808 4.02 0% 1% 100% 1% binary-trees source secs mem gz busy cpu load Java 2.49 2,490,296 835 7.88 92% 75% 78% 72% C++ g++ 1.16 200,288 890 4.19 89% 88% 87% 98% spectral-norm source secs mem gz busy cpu load Java 1.66 38,280 950 6.36 97% 95% 96% 96% C++ g++ 0.72 2,348 1044 2.84 100% 99% 99% 99% reverse-complement source secs mem gz busy cpu load Java 1.53 720,672 2183 3.57 52% 63% 59% 59% C++ g++ 0.63 499,668 2093 0.64 2% 0% 0% 100% k-nucleotide source secs mem gz busy cpu load Java 4.88 409,508 1812 15.86 75% 88% 86% 77% C++ g++ 1.98 156,108 1631 5.92 96% 67% 68% 68% mandelbrot source secs mem gz busy cpu load Java 4.15 70,040 796 16.34 98% 98% 99% 98% C++ g++ 0.89 34,540 3542 3.47 98% 98% 97% 99% regex-redux source secs mem gz busy cpu load Java 5.58 656,192 929 17.84 83% 83% 80% 74% C++ g++ 1.03 275,752 2850 2.19 36% 37% 100% 40% 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) C++ g++ g++ (Ubuntu 9.3.0-10ubuntu2) 9.3.0 all Java programs & measurements all C++ g++ programs & measurements