Fortran VS Nim benchmarks

Current benchmark data was generated on Sun Sep 27 2026, full log can be found HERE

CONTRIBUTIONS are WELCOME!

CPU INFO:[x86_64][4 cores] Intel(R) Core(TM) i7-3687U CPU @ 2.10GHz (Model 58)

* -m in a file name stands for multi-threading or multi-processing

* -i in a file name stands for direct intrinsics usage. (Usage of simd intrinsics via libraries is not counted)

* -ffi in a file name stands for non-stdlib FFI usage

* (You may find time < time(user) + time(sys) for some non-parallelized programs, the overhead is from GC or JIT compiler, which are allowed to take advantage of multi-cores as that's more close to real-world scenarios.)

show numbers without parallelization

show numbers with parallelization

fasta

Input: 2500000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
fortran	4.f90	177ms	14ms	1.5MB	167ms	0ms	gfortran 13.3.0
nim	2.nim	252ms	0.3ms	1.4MB	240ms	0ms	nim/clang 2.2.4
nim	2.nim	252ms	8.0ms	2.0MB	233ms	0ms	nim 2.2.4
nim	1.nim	606ms	6.1ms	1.3MB	500ms	90ms	nim/clang 2.2.4
nim	1.nim	644ms	18ms	2.1MB	523ms	107ms	nim 2.2.4

Input: 250000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
fortran	4.f90	23ms	3.7ms	2.7MB	13ms	0ms	gfortran 13.3.0
nim	2.nim	29ms	2.1ms	1.4MB	20ms	0ms	nim/clang 2.2.4
nim	2.nim	31ms	3.8ms	2.1MB	23ms	0ms	nim 2.2.4
nim	1.nim	66ms	1.5ms	2.1MB	50ms	0ms	nim 2.2.4
nim	1.nim	76ms	15ms	1.3MB	57ms	7ms	nim/clang 2.2.4

helloworld

Input: QwQ

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
nim	1.nim	1.5ms	0.1ms	1.3MB	0ms	0ms	nim/clang 2.2.4
fortran	1.f90	1.7ms	0.3ms	1.6MB	0ms	0ms	gfortran 13.3.0
nim	1.nim	2.5ms	0.5ms	2.1MB	0ms	0ms	nim 2.2.4

nbody

Input: 5000000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
nim	2.nim	494ms	1.4ms	2.1MB	480ms	0ms	nim 2.2.4
nim	2.nim	542ms	9.6ms	1.4MB	530ms	0ms	nim/clang 2.2.4
fortran	2.f90	610ms	47ms	1.5MB	600ms	0ms	gfortran 13.3.0

Input: 500000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
nim	2.nim	55ms	2.9ms	2.1MB	47ms	0ms	nim 2.2.4
nim	2.nim	58ms	1.0ms	1.3MB	50ms	0ms	nim/clang 2.2.4
fortran	2.f90	65ms	1.1ms	1.6MB	57ms	0ms	gfortran 13.3.0

spectral-norm

Input: 8000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
fortran	3-m.f90	6051ms	7.3ms	1.5MB	23903ms	3ms	gfortran 13.3.0
nim	1.nim	11029ms	35ms	1.3MB	11017ms	0ms	nim/clang 2.2.4
nim	1.nim	11039ms	7.6ms	3.4MB	11027ms	0ms	nim 2.2.4
fortran	2.f90	11153ms	19ms	2.5MB	11143ms	0ms	gfortran 13.3.0

Input: 4000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
fortran	3-m.f90	1522ms	3.5ms	1.5MB	5970ms	3ms	gfortran 13.3.0
nim	1.nim	2764ms	2.5ms	1.4MB	2753ms	0ms	nim/clang 2.2.4
nim	1.nim	2767ms	4.2ms	2.1MB	2753ms	0ms	nim 2.2.4
fortran	2.f90	2795ms	3.4ms	1.6MB	2783ms	0ms	gfortran 13.3.0

Input: 2000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
fortran	3-m.f90	391ms	2.4ms	1.6MB	1477ms	0ms	gfortran 13.3.0
nim	1.nim	695ms	0.3ms	1.3MB	683ms	0ms	nim/clang 2.2.4
nim	1.nim	696ms	2.1ms	2.1MB	687ms	0ms	nim 2.2.4
fortran	2.f90	703ms	3.3ms	1.5MB	687ms	0ms	gfortran 13.3.0