The Computer Language
Benchmarks Game

C# .NET Core 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
C# .NET Core 2.24 295,716 1869 4.29 27% 50% 44% 70%
Java 10.48 645,680 740 31.62 72% 87% 74% 68%
k-nucleotide
source secs mem gz busy cpu load
C# .NET Core 5.68 186,384 2574 18.86 91% 90% 80% 71%
Java 8.70 446,004 1812 27.18 83% 78% 78% 73%
pidigits
source secs mem gz busy cpu load
C# .NET Core 2.10 38,208 973 2.15 3% 97% 2% 0%
Java 3.07 39,680 938 3.30 99% 3% 0% 5%
mandelbrot
source secs mem gz busy cpu load
C# .NET Core 5.54 66,320 816 21.63 99% 97% 97% 98%
Java 5.98 79,184 796 23.43 98% 98% 97% 99%
reverse-complement
source secs mem gz busy cpu load
C# .NET Core 3.04 1,036,072 1621 7.35 26% 70% 51% 95%
Java 3.27 740,524 2183 7.44 44% 57% 84% 43%
binary-trees
source secs mem gz busy cpu load
C# .NET Core 8.05 805,016 810 26.80 83% 79% 82% 89%
Java 8.28 907,060 835 27.59 86% 90% 80% 77%
n-body
source secs mem gz busy cpu load
C# .NET Core 21.45 36,580 1542 22.28 4% 0% 0% 100%
Java 21.94 35,588 1429 22.39 100% 0% 1% 1%
spectral-norm
source secs mem gz busy cpu load
C# .NET Core 4.11 36,056 878 15.90 96% 98% 98% 96%
Java 4.19 36,740 950 16.36 98% 97% 98% 98%
fannkuch-redux
source secs mem gz busy cpu load
C# .NET Core 16.73 35,736 1189 66.42 99% 100% 99% 99%
Java 17.04 34,236 1282 67.30 99% 98% 100% 98%
fasta
source secs mem gz busy cpu load
C# .NET Core 2.28 67,552 2098 8.19 95% 89% 89% 87%
Java 2.23 45,156 2473 5.99 51% 62% 59% 97%
C# .NET Core

.NET Core SDK 2.2.202
Host Version: 2.2.3; Commit: 6b8ad509b6
<ServerGarbageCollection>true
<ConcurrentGarbageCollection>true

Java

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