The Computer Language
Benchmarks Game

Swift 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.

mandelbrot
source secs mem gz busy cpu load
Swift 3.20 39,384 1138 12.70 100% 99% 99% 99%
Java 6.83 79,108 796 26.86 97% 99% 99% 99%
pidigits
source secs mem gz busy cpu load
Swift 1.75 8,976 600 1.79 1% 1% 0% 100%
Java 3.07 39,320 938 3.31 2% 5% 3% 98%
fannkuch-redux
source secs mem gz busy cpu load
Swift 10.11 8,048 1097 40.10 98% 100% 99% 100%
Java 14.33 34,888 1282 56.56 99% 98% 99% 98%
spectral-norm
source secs mem gz busy cpu load
Swift 3.96 7,996 601 15.79 100% 99% 100% 100%
Java 4.19 36,680 950 16.31 98% 97% 97% 98%
n-body
source secs mem gz busy cpu load
Swift 22.03 12,268 1355 22.25 0% 0% 100% 1%
Java 21.95 35,604 1429 22.75 2% 1% 100% 1%
reverse-complement
source secs mem gz busy cpu load
Swift 3.82 714,868 1286 4.57 81% 3% 36% 0%
Java 3.16 712,368 2183 7.08 65% 47% 42% 70%
fasta
source secs mem gz busy cpu load
Swift 3.22 8,792 1945 4.82 36% 29% 43% 41%
Java 2.22 45,172 2473 5.99 61% 50% 98% 60%
k-nucleotide
source secs mem gz busy cpu load
Swift 21.77 257,384 1367 82.66 94% 97% 94% 95%
Java 9.33 447,976 1812 29.36 73% 83% 82% 77%
regex-redux
source secs mem gz busy cpu load
Swift 43.98 880,444 715 78.94 9% 57% 29% 85%
Java 10.31 644,560 740 31.47 72% 72% 92% 70%
binary-trees
source secs mem gz busy cpu load
Swift 44.93 733,728 714 133.24 78% 70% 74% 75%
Java 8.32 953,620 835 28.37 95% 87% 81% 77%
Swift

Swift version 5.1.1-dev (LLVM b47beb8a70, Swift 7e43e9bcfd)
Target: x86_64-unknown-linux-gnu

Java

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