Rust versus C clang 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. binary-trees source secs mem gz busy cpu load Rust 1.02 198,720 765 3.64 87% 86% 85% 99% C clang 7.69 351,340 908 27.75 92% 91% 88% 91% regex-redux source secs mem gz busy cpu load Rust 0.77 147,384 2458 2.00 55% 59% 55% 91% C clang 3.12 103,044 1115 3.14 100% 0% 1% 0% mandelbrot source secs mem gz busy cpu load Rust 0.93 32,648 763 3.70 99% 100% 100% 100% C clang 3.49 29,608 822 13.94 100% 100% 100% 100% reverse-complement source secs mem gz busy cpu load Rust 0.45 498,880 3040 0.76 61% 23% 60% 24% C clang 1.07 994,176 750 1.55 15% 88% 12% 30% fannkuch-redux source secs mem gz busy cpu load Rust 7.61 1,200 1020 29.86 94% 100% 99% 99% C clang 8.85 936 1557 34.65 94% 100% 98% 99% fasta source secs mem gz busy cpu load Rust 0.76 1,836 2529 1.53 99% 63% 38% 0% C clang 0.78 1,160 1463 0.79 0% 1% 100% 0% pidigits source secs mem gz busy cpu load Rust 0.72 2,660 799 0.77 100% 0% 0% 7% C clang 0.61 2,340 1090 2.41 100% 98% 100% 100% n-body source secs mem gz busy cpu load Rust 3.42 872 1753 3.44 0% 100% 0% 0% C clang 2.21 768 1633 2.23 0% 0% 0% 100% spectral-norm source secs mem gz busy cpu load Rust 0.71 2,660 817 2.86 100% 100% 100% 100% C clang Make Error k-nucleotide source secs mem gz busy cpu load Rust 2.68 159,104 1691 10.03 92% 91% 100% 91% C clang Make Error Rust rustc 1.53.0 (53cb7b09b 2021-06-17) LLVM version: 12.0.1 C clang Ubuntu clang version 12.0.0-1ubuntu all Rust programs & measurements all C clang programs & measurements