more-similar less-idiosyncratic

When programs are idiomatic someone will say they are not comparable.

Are they similar-enough to be comparable for your purposes? Will someone then say the programs are not idiomatic.

If only more-idiomatic was not less-comparable!

Here are a few naive un-optimised single-thread #8 programs transliterated lowest-common-denominator style into different programming languages from the same original —

elapsed secs / fastest		insignificant io
×	source
1.0	C# aot	spectral-norm
1.0	C gcc	n-body
1.0	Swift	spectral-norm
1.0	Go	spectral-norm
1.0	Swift	fannkuch-redux
1.0	C gcc	spectral-norm
1.0	Java	spectral-norm
1.1	C gcc	fannkuch-redux
1.2	Swift	n-body
1.2	Node.js	spectral-norm
1.3	C# aot	n-body
1.3	C# aot	fannkuch-redux
1.3	Java	fannkuch-redux
1.3	Go	fannkuch-redux
1.4	Dart	n-body
1.4	Java	n-body
1.7	Node.js	fannkuch-redux
1.7	Node.js	n-body
1.7	Go	n-body
2.0	Dart	fannkuch-redux
2.0	Dart	spectral-norm
12	PHP	n-body
15	Java -Xint	spectral-norm
16	PHP	spectral-norm
20	Java -Xint	fannkuch-redux
29	Java -Xint	n-body
32	Ruby yjit	spectral-norm
43	PHP	fannkuch-redux
56	Ruby yjit	fannkuch-redux
64	Python 3	fannkuch-redux
70	Ruby yjit	n-body
71	Python 3	spectral-norm
94	Python 3	n-body
314	Matz's Ruby	spectral-norm
586	Matz's Ruby	n-body

Seemingly similar programs behave differently when the language implementations behave differently. Do they have the same default stdio buffering? Do the programs need to be written differently and run differently to make them behave the same.

To be less similar so they are more comparable!

elapsed secs / fastest		significant io
×	source
1.0	C gcc	mandelbrot
1.0	PHP	k-nucleotide
1.0	C gcc	fasta
1.0	C# aot	mandelbrot
1.0	Swift	mandelbrot
1.1	Go	mandelbrot
1.1	Java	mandelbrot
1.3	C# aot	k-nucleotide
1.4	Java	k-nucleotide
2.6	C# aot	fasta
2.9	Node.js	mandelbrot
3.2	PHP	mandelbrot
3.3	Swift	k-nucleotide
3.3	Java	fasta
4.0	Go	fasta
4.3	Python 3	k-nucleotide
8.0	Dart	mandelbrot
10	Dart	k-nucleotide
14	Ruby yjit	k-nucleotide
23	Swift	fasta
25	Java -Xint	mandelbrot
56	Python 3	fasta
57	PHP	fasta
58	Ruby yjit	fasta
60	Ruby yjit	mandelbrot
61	Python 3	mandelbrot
115	Node.js	fasta
146	Java -Xint	fasta
197	Dart	fasta

Such comparisons raise a nest of issues all their own: for example, is it really the same program when written in the two compared languages? (Will Partain, 1992.)

elapsed secs / fastest		Geometric Mean
1.0	C gcc
1.3	C# aot
1.4	Java
1.6	Go
2.1	Swift
4.1	Node.js
6.7	Dart
11	PHP
32	Java -Xint
43	Ruby yjit
43	Python 3
429	Matz's Ruby