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 3.14 39,140 1138 12.45 100% 99% 99% 99%
Java 5.98 79,184 796 23.43 98% 98% 97% 99%
pidigits
source secs mem gz busy cpu load
Swift 1.75 8,632 600 1.77 0% 99% 2% 0%
Java 3.07 39,680 938 3.30 99% 3% 0% 5%
fannkuch-redux
source secs mem gz busy cpu load
Swift 10.09 7,500 1097 40.15 100% 99% 99% 100%
Java 17.04 34,236 1282 67.30 99% 98% 100% 98%
spectral-norm
source secs mem gz busy cpu load
Swift 3.96 8,080 601 15.78 99% 100% 100% 99%
Java 4.19 36,740 950 16.36 98% 97% 98% 98%
n-body
source secs mem gz busy cpu load
Swift 22.03 13,420 1355 22.52 1% 1% 0% 100%
Java 21.94 35,588 1429 22.39 100% 0% 1% 1%
reverse-complement
source secs mem gz busy cpu load
Swift 3.72 791,096 1286 4.58 3% 80% 37% 3%
Java 3.27 740,524 2183 7.44 44% 57% 84% 43%
fasta
source secs mem gz busy cpu load
Swift 3.08 8,464 1945 4.76 33% 23% 49% 50%
Java 2.23 45,156 2473 5.99 51% 62% 59% 97%
k-nucleotide
source secs mem gz busy cpu load
Swift 22.11 257,660 1367 83.53 92% 99% 94% 93%
Java 8.70 446,004 1812 27.18 83% 78% 78% 73%
regex-redux
source secs mem gz busy cpu load
Swift 41.68 880,268 715 73.43 83% 1% 66% 27%
Java 10.48 645,680 740 31.62 72% 87% 74% 68%
binary-trees
source secs mem gz busy cpu load
Swift 45.22 733,972 714 135.66 95% 68% 70% 68%
Java 8.28 907,060 835 27.59 86% 90% 80% 77%
Swift

Swift version 5.1-dev (LLVM 2238e51577, Swift a5aa0c6a64)
Target: x86_64-unknown-linux-gnu

Java

openjdk 12 2019-03-19
OpenJDK Runtime Environment (build 12+33)
OpenJDK 64-Bit Server VM (build 12+33, mixed mode, sharing)