C++ VS C# 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

fannkuch-redux

Input: 11

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	1-im.cpp	345ms	20ms	1.3MB	1217ms	0ms	g++ 13.3.0
cpp	1-im.cpp	388ms	14ms	6.1MB	1353ms	7ms	clang++ 18.1.3

Input: 10

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	1-im.cpp	35ms	2.1ms	1.3MB	103ms	0ms	g++ 13.3.0
cpp	1-im.cpp	42ms	3.1ms	6.1MB	120ms	3ms	clang++ 18.1.3

helloworld

Input: QwQ

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	1.cpp	1.1ms	0.2ms	1.5MB	0ms	0ms	g++ 13.3.0
cpp	1.cpp	1.7ms	0.3ms	1.5MB	0ms	0ms	clang++ 18.1.3
csharp	1.cs	46ms	3.5ms	24.6MB	30ms	2ms	dotnet 9.0.318

nbody

Input: 5000000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	0-i.cpp	219ms	0.7ms	1.0MB	210ms	0ms	g++ 13.3.0
cpp	0-i.cpp	225ms	20ms	1.6MB	217ms	0ms	clang++ 18.1.3
cpp	1.cpp	387ms	4.1ms	1.6MB	377ms	0ms	clang++ 18.1.3
cpp	1.cpp	734ms	2.2ms	1.1MB	723ms	0ms	g++ 13.3.0
csharp	8.cs	783ms	1.5ms	29.6MB	760ms	10ms	dotnet 9.0.318
csharp	9.cs	997ms	4.7ms	29.6MB	967ms	17ms	dotnet 9.0.318

Input: 500000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	0-i.cpp	24ms	1.0ms	1.6MB	13ms	0ms	clang++ 18.1.3
cpp	0-i.cpp	24ms	0.2ms	1.1MB	10ms	0ms	g++ 13.3.0
cpp	1.cpp	42ms	0.7ms	1.5MB	30ms	0ms	clang++ 18.1.3
cpp	1.cpp	77ms	0.2ms	1.1MB	70ms	0ms	g++ 13.3.0
csharp	8.cs	159ms	7.2ms	30.1MB	140ms	3ms	dotnet 9.0.318
csharp	9.cs	228ms	3.1ms	29.9MB	203ms	10ms	dotnet 9.0.318

nsieve

Input: 12

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	1.cpp	796ms	7.4ms	7.5MB	780ms	0ms	clang++ 18.1.3
csharp	2.cs	819ms	3.8ms	33.5MB	797ms	13ms	dotnet 9.0.318
cpp	1.cpp	847ms	19ms	7.1MB	833ms	0ms	g++ 13.3.0
csharp	1.cs	1042ms	3.6ms	96.6MB	1020ms	13ms	dotnet 9.0.318

Input: 10

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	1.cpp	160ms	1.7ms	4.1MB	150ms	0ms	clang++ 18.1.3
cpp	1.cpp	171ms	8.0ms	3.6MB	160ms	0ms	g++ 13.3.0
csharp	2.cs	205ms	0.9ms	32.5MB	183ms	7ms	dotnet 9.0.318
csharp	1.cs	235ms	2.8ms	37.6MB	213ms	10ms	dotnet 9.0.318

spectral-norm

Input: 8000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	6-im.cpp	2915ms	1.5ms	5.5MB	11537ms	7ms	clang++ 18.1.3
cpp	6-im.cpp	2917ms	0.5ms	2.4MB	11547ms	3ms	g++ 13.3.0
cpp	8-m.cpp	2934ms	0.7ms	3.3MB	11603ms	3ms	clang++ 18.1.3
cpp	8-m.cpp	2973ms	15ms	2.4MB	11770ms	3ms	g++ 13.3.0
csharp	3-m.cs	5928ms	20ms	33.5MB	23127ms	17ms	dotnet 9.0.318

Input: 4000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	6-im.cpp	734ms	0.8ms	1.4MB	2880ms	0ms	g++ 13.3.0
cpp	8-m.cpp	741ms	3.9ms	3.3MB	2880ms	3ms	clang++ 18.1.3
cpp	8-m.cpp	748ms	5.3ms	1.4MB	2943ms	0ms	g++ 13.3.0
cpp	6-im.cpp	748ms	21ms	3.4MB	2880ms	7ms	clang++ 18.1.3
csharp	3-m.cs	1536ms	1.6ms	34.0MB	5793ms	13ms	dotnet 9.0.318

Input: 2000

lang	code	time	stddev	peak-mem mem	time(user)	time(sys)	compiler compiler/runtime
cpp	6-im.cpp	189ms	0.5ms	1.4MB	713ms	0ms	g++ 13.3.0
cpp	8-m.cpp	192ms	2.2ms	1.4MB	723ms	0ms	g++ 13.3.0
cpp	8-m.cpp	197ms	5.8ms	3.4MB	717ms	0ms	clang++ 18.1.3
cpp	6-im.cpp	198ms	15ms	5.4MB	723ms	3ms	clang++ 18.1.3
csharp	3-m.cs	449ms	3.7ms	33.3MB	1487ms	17ms	dotnet 9.0.318