The Computer Language
Benchmarks Game

Rust versus Java 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.

regex-redux
source secs mem gz busy cpu load
Rust 2.10 153,076 986 3.14 30% 17% 83% 19%
Java 10.31 644,560 740 31.47 72% 72% 92% 70%
mandelbrot
source secs mem gz busy cpu load
Rust 1.70 30,492 1332 6.70 98% 98% 98% 100%
Java 6.83 79,108 796 26.86 97% 99% 99% 99%
n-body
source secs mem gz busy cpu load
Rust 6.07 944 1753 6.14 0% 0% 100% 1%
Java 21.95 35,604 1429 22.75 2% 1% 100% 1%
binary-trees
source secs mem gz busy cpu load
Rust 3.33 199,664 721 12.08 87% 100% 88% 87%
Java 8.32 953,620 835 28.37 95% 87% 81% 77%
spectral-norm
source secs mem gz busy cpu load
Rust 1.97 2,196 1126 7.87 100% 100% 99% 99%
Java 4.19 36,680 950 16.31 98% 97% 97% 98%
reverse-complement
source secs mem gz busy cpu load
Rust 1.68 994,820 1376 2.83 28% 95% 24% 22%
Java 3.16 712,368 2183 7.08 65% 47% 42% 70%
pidigits
source secs mem gz busy cpu load
Rust 1.75 3,052 1366 1.78 1% 0% 1% 100%
Java 3.07 39,320 938 3.31 2% 5% 3% 98%
k-nucleotide
source secs mem gz busy cpu load
Rust 5.40 135,184 1749 17.13 60% 92% 69% 96%
Java 9.33 447,976 1812 29.36 73% 83% 82% 77%
fasta
source secs mem gz busy cpu load
Rust 1.51 2,044 1906 4.60 74% 83% 73% 74%
Java 2.22 45,172 2473 5.99 61% 50% 98% 60%
fannkuch-redux
source secs mem gz busy cpu load
Rust 11.13 944 1020 43.64 100% 93% 100% 100%
Java 14.33 34,888 1282 56.56 99% 98% 99% 98%
Rust

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

Java

openjdk 13 2019-09-17
OpenJDK Runtime Environment (build 13+33)
OpenJDK 64-Bit Server VM (build 13+33, mixed mode, sharing)