The Computer Language
Benchmarks Game

Rust versus C++ g++ fastest programs

Back in April 2010, Russ Cox charitably suggested that only fannkuch-redux, fasta, k-nucleotide, mandlebrot, nbody, reverse-complement and spectral-norm were close to fair comparisons. As someone who implemented programming languages, his interest was "measuring the quality of the generated code when both compilers are presented with what amounts to the same program."

Differences in approach - to memory management, parallel programming, regex, arbitrary precision arithmetic, implementation technique - don't fit in that kind-of fair comparison — but we still have to deal with them.

These are only the fastest programs. There may be additional measurements for programs which seem more-like a fair comparison to you. Always look at the source code.

n-body
source secs mem gz busy cpu load
Rust 6.07 944 1753 6.14 0% 0% 100% 1%
C++ g++ 7.92 1,116 1773 8.51 6% 1% 1% 100%
binary-trees
source secs mem gz busy cpu load
Rust 3.33 199,664 721 12.08 87% 100% 88% 87%
C++ g++ 3.92 114,136 809 12.90 82% 75% 73% 98%
pidigits
source secs mem gz busy cpu load
Rust 1.75 3,052 1366 1.78 1% 0% 1% 100%
C++ g++ 1.89 4,552 513 1.92 1% 100% 1% 0%
spectral-norm
source secs mem gz busy cpu load
Rust 1.97 2,196 1126 7.87 100% 100% 99% 99%
C++ g++ 1.98 2,268 1044 7.89 100% 99% 99% 99%
fasta
source secs mem gz busy cpu load
Rust 1.51 2,044 1906 4.60 74% 83% 73% 74%
C++ g++ 1.46 2,216 2711 4.40 75% 75% 76% 75%
fannkuch-redux
source secs mem gz busy cpu load
Rust 11.13 944 1020 43.64 100% 93% 100% 100%
C++ g++ 10.69 1,896 980 42.28 100% 100% 96% 100%
reverse-complement
source secs mem gz busy cpu load
Rust 1.68 994,820 1376 2.83 28% 95% 24% 22%
C++ g++ 1.61 996,244 1226 2.76 25% 24% 96% 27%
mandelbrot
source secs mem gz busy cpu load
Rust 1.70 30,492 1332 6.70 98% 98% 98% 100%
C++ g++ 1.51 25,828 1791 6.03 100% 100% 100% 100%
regex-redux
source secs mem gz busy cpu load
Rust 2.10 153,076 986 3.14 30% 17% 83% 19%
C++ g++ 1.83 203,932 1315 4.44 44% 99% 48% 51%
k-nucleotide
source secs mem gz busy cpu load
Rust 5.40 135,184 1749 17.13 60% 92% 69% 96%
C++ g++ 3.81 156,348 1624 11.78 70% 70% 73% 96%
Rust

rustc 1.39.0 (4560ea788 2019-11-04)
LLVM version: 9.0

C++ g++

g++ (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008