C++ VS Wasm benchmarks

Current benchmark data was generated on Sun Jul 13 2025, full log can be found HERE

CONTRIBUTIONS are WELCOME!

[x86_64][4 cores] AMD EPYC 7763 64-Core Processor (Model 1)

* -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.)

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 1-im.cpp 402ms 3.9ms 4.0MB 1563ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 1-im.cpp 403ms 1.7ms 2.5MB 1547ms 0ms g++ 11.4.0
wasm 1.rs 4157ms 18ms 17.8MB 4143ms 0ms wasmtime 34.0.1

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 1-im.cpp 40ms 1.4ms 2.6MB 130ms 0ms g++ 11.4.0
cpp 1-im.cpp 40ms 1.4ms 3.9MB 133ms 0ms clang++ 14.0.0-1ubuntu1.1
wasm 1.rs 349ms 4.0ms 17.7MB 337ms 0ms wasmtime 34.0.1

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 1.cpp 1.0ms 0.0ms 1.4MB 0ms 0ms g++ 11.4.0
cpp 1.cpp 1.3ms 0.1ms 2.3MB 0ms 0ms clang++ 14.0.0-1ubuntu1.1
wasm 1.rs 6.7ms 0.5ms 18.2MB 0ms 0ms wasmtime 34.0.1

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 0-i.cpp 167ms 0.3ms 1.5MB 160ms 0ms g++ 11.4.0
cpp 0-i.cpp 171ms 0.8ms 2.3MB 160ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 1.cpp 314ms 1.3ms 1.8MB 307ms 0ms g++ 11.4.0
cpp 1.cpp 316ms 1.0ms 2.3MB 310ms 0ms clang++ 14.0.0-1ubuntu1.1
wasm 1.rs 405ms 1.9ms 18.0MB 390ms 0ms wasmtime 34.0.1
wasm 2.rs 564ms 4.6ms 18.1MB 553ms 0ms wasmtime 34.0.1

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 0-i.cpp 18ms 0.1ms 1.5MB 10ms 0ms g++ 11.4.0
cpp 0-i.cpp 19ms 0.4ms 2.3MB 10ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 1.cpp 34ms 0.6ms 2.3MB 30ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 1.cpp 34ms 0.9ms 1.8MB 30ms 0ms g++ 11.4.0
wasm 1.rs 47ms 0.1ms 18.1MB 37ms 0ms wasmtime 34.0.1
wasm 2.rs 65ms 1.7ms 18.1MB 50ms 0ms wasmtime 34.0.1

nsieve

Input: 12

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
wasm 2.rs 387ms 3.2ms 22.9MB 373ms 0ms wasmtime 34.0.1
wasm 1.rs 463ms 2.4ms 57.0MB 447ms 3ms wasmtime 34.0.1
cpp 1.cpp 484ms 1.6ms 7.3MB 477ms 0ms g++ 11.4.0
cpp 1.cpp 528ms 2.2ms 7.7MB 520ms 0ms clang++ 14.0.0-1ubuntu1.1

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
wasm 1.rs 92ms 3.2ms 27.9MB 80ms 0ms wasmtime 34.0.1
wasm 2.rs 100ms 2.0ms 19.3MB 90ms 0ms wasmtime 34.0.1
cpp 1.cpp 119ms 1.7ms 3.6MB 110ms 0ms g++ 11.4.0
cpp 1.cpp 133ms 0.8ms 4.0MB 120ms 0ms clang++ 14.0.0-1ubuntu1.1

spectral-norm

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 8-m.cpp 468ms 1.6ms 3.4MB 1820ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 8-m.cpp 482ms 0.8ms 2.1MB 1880ms 0ms g++ 11.4.0
cpp 6-im.cpp 921ms 2.0ms 2.3MB 3627ms 0ms g++ 11.4.0
cpp 6-im.cpp 924ms 12ms 3.4MB 3610ms 3ms clang++ 14.0.0-1ubuntu1.1
wasm 2.rs 3597ms 3.4ms 17.7MB 3583ms 0ms wasmtime 34.0.1
wasm 7.rs 4892ms 1.4ms 19.8MB 4880ms 0ms wasmtime 34.0.1

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 8-m.cpp 123ms 0.9ms 3.6MB 460ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 8-m.cpp 128ms 0.7ms 2.0MB 480ms 0ms g++ 11.4.0
cpp 6-im.cpp 238ms 0.5ms 2.1MB 913ms 0ms g++ 11.4.0
cpp 6-im.cpp 241ms 5.7ms 3.4MB 910ms 0ms clang++ 14.0.0-1ubuntu1.1
wasm 2.rs 906ms 1.0ms 18.3MB 893ms 0ms wasmtime 34.0.1
wasm 7.rs 1231ms 2.6ms 17.7MB 1217ms 0ms wasmtime 34.0.1

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
cpp 8-m.cpp 39ms 0.4ms 2.0MB 130ms 0ms g++ 11.4.0
cpp 8-m.cpp 39ms 4.7ms 3.4MB 113ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 6-im.cpp 64ms 0.4ms 3.4MB 227ms 0ms clang++ 14.0.0-1ubuntu1.1
cpp 6-im.cpp 67ms 0.1ms 2.0MB 240ms 0ms g++ 11.4.0
wasm 2.rs 234ms 0.9ms 17.8MB 220ms 0ms wasmtime 34.0.1
wasm 7.rs 314ms 0.5ms 18.1MB 300ms 0ms wasmtime 34.0.1