C gcc versus Rust fastest programs Always look at the source code. These are only the fastest programs. If it's manually vectorized SIMD, does the host language matter? Look at the other programs. They may seem more-like a fair comparison to you. spectral-norm source secs mem gz busy cpu load C gcc 0.41 1,016 1197 1.60 98% 95% 98% 95% Rust 0.71 2,488 932 2.85 100% 100% 99% 100% n-body source secs mem gz busy cpu load C gcc 2.13 992 1633 2.22 1% 1% 2% 100% Rust 2.90 1,052 1874 2.98 0% 1% 100% 1% pidigits source secs mem gz busy cpu load C gcc 0.56 2,440 1090 2.26 100% 100% 100% 100% Rust 0.70 2,580 799 0.70 0% 100% 0% 0% reverse-complement source secs mem gz busy cpu load C gcc 0.41 499,072 1965 0.59 15% 90% 22% 17% Rust 0.45 498,736 3040 0.78 26% 48% 76% 24% fasta source secs mem gz busy cpu load C gcc 0.78 1,244 1463 0.82 0% 1% 4% 100% Rust 0.77 1,996 2529 1.56 100% 1% 4% 99% regex-redux source secs mem gz busy cpu load C gcc 0.80 152,240 1397 2.06 97% 55% 50% 56% Rust 0.78 146,632 2458 2.01 56% 60% 90% 53% mandelbrot source secs mem gz busy cpu load C gcc 1.30 30,924 1135 5.18 100% 100% 100% 100% Rust 0.91 32,676 757 3.63 100% 99% 99% 100% binary-trees source secs mem gz busy cpu load C gcc 1.58 168,780 809 4.58 100% 62% 67% 62% Rust 1.11 198,404 765 3.93 86% 98% 86% 85% k-nucleotide source secs mem gz busy cpu load C gcc 3.96 130,000 1506 12.52 74% 54% 99% 90% Rust 2.69 159,044 1691 10.00 92% 97% 92% 92% fannkuch-redux source secs mem gz busy cpu load C gcc 7.58 1,048 910 29.67 99% 100% 94% 99% Rust 3.80 1,352 1253 15.13 100% 99% 99% 99% C gcc gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0 Rust rustc 1.58.0 (02072b482 2022-01-11) LLVM version: 13.0.0 all C gcc programs & measurements all Rust programs & measurements