F# .NET versus Java 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. regex-redux source secs mem gz busy cpu load F# .NET 2.85 1,301,192 611 7.36 51% 92% 59% 56% Java 5.31 793,572 929 17.50 79% 78% 83% 89% n-body source secs mem gz busy cpu load F# .NET 5.07 35,072 1383 5.18 1% 99% 1% 1% Java 6.77 35,432 1489 6.82 100% 1% 0% 0% k-nucleotide source secs mem gz busy cpu load F# .NET 3.65 184,680 1907 12.58 94% 84% 85% 83% Java 4.85 354,288 1812 15.92 80% 85% 87% 76% fannkuch-redux source secs mem gz busy cpu load F# .NET 8.65 31,784 1097 33.57 98% 99% 94% 98% Java 10.38 35,388 1282 40.84 99% 99% 98% 97% pidigits source secs mem gz busy cpu load F# .NET 0.82 34,428 905 0.83 1% 2% 96% 1% Java 0.93 36,088 764 0.97 4% 0% 1% 99% mandelbrot source secs mem gz busy cpu load F# .NET 3.77 64,912 933 14.73 99% 97% 98% 97% Java 4.12 70,952 796 16.22 98% 98% 98% 99% fasta source secs mem gz busy cpu load F# .NET 1.14 120,528 1350 4.18 94% 94% 89% 91% Java 1.19 44,740 2543 3.50 75% 63% 87% 70% spectral-norm source secs mem gz busy cpu load F# .NET 1.55 31,916 853 5.83 92% 98% 93% 93% Java 1.58 39,408 756 5.97 94% 94% 96% 94% reverse-complement source secs mem gz busy cpu load F# .NET 1.51 1,030,852 1140 4.19 93% 36% 58% 91% Java 1.53 687,864 2183 3.50 80% 46% 57% 46% binary-trees source secs mem gz busy cpu load F# .NET 6.06 1,469,616 516 16.18 63% 69% 62% 72% Java 2.48 1,725,776 835 7.86 74% 75% 97% 72% F# .NET .NET SDK 5.0.100 Host Version: 5.0.0; Commit: cf258a14b7 <ServerGarbageCollection>true</ServerGarbageCollection> 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) all F# .NET programs & measurements all Java programs & measurements