OCaml VS Nim 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.)

binarytrees

Input: 18

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 786ms 11ms 34.9MB 770ms 3ms nim 2.2.4
nim 2.nim 947ms 6.3ms 35.2MB 923ms 10ms nim/clang 2.2.4
ocaml 1.ml 3087ms 52ms 157.2MB 3003ms 70ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 73ms 0.2ms 5.5MB 60ms 0ms nim 2.2.4
nim 2.nim 93ms 1.5ms 5.8MB 80ms 0ms nim/clang 2.2.4
ocaml 1.ml 221ms 1.6ms 19.1MB 207ms 0ms ocaml 5.3.0

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 2.ml 2909ms 4.1ms 4.9MB 2903ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 2.ml 245ms 0.8ms 5.2MB 237ms 0ms ocaml 5.3.0

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 188ms 2.6ms 1.5MB 177ms 0ms nim 2.2.4
nim 2.nim 243ms 2.2ms 1.8MB 233ms 0ms nim/clang 2.2.4
ocaml 6.ml 346ms 1.9ms 24.8MB 330ms 0ms ocaml 5.3.0
nim 1.nim 537ms 2.6ms 1.8MB 447ms 73ms nim/clang 2.2.4
nim 1.nim 560ms 2.7ms 1.5MB 470ms 73ms nim 2.2.4

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 21ms 0.8ms 1.5MB 10ms 0ms nim 2.2.4
nim 2.nim 27ms 1.0ms 1.8MB 20ms 0ms nim/clang 2.2.4
ocaml 6.ml 39ms 0.7ms 7.4MB 30ms 0ms ocaml 5.3.0
nim 1.nim 57ms 0.9ms 1.8MB 40ms 0ms nim/clang 2.2.4
nim 1.nim 59ms 0.7ms 1.5MB 47ms 0ms nim 2.2.4

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 1.0ms 0.0ms 1.6MB 0ms 0ms nim 2.2.4
nim 1.nim 1.1ms 0.0ms 1.8MB 0ms 0ms nim/clang 2.2.4
ocaml 1.ml 1.8ms 0.1ms 5.0MB 0ms 0ms ocaml 5.3.0

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 112ms 1.7ms 1.6MB 103ms 0ms nim/clang 2.2.4
nim 2.nim 114ms 2.9ms 1.4MB 110ms 0ms nim 2.2.4
ocaml 1.ml 173ms 2.7ms 6.4MB 163ms 0ms ocaml 5.3.0
nim 1.nim timeout 0.0ms 1.3MB 4990ms 0ms nim 2.2.4
nim 1.nim timeout 0.0ms 1.5MB 4990ms 0ms nim/clang 2.2.4

Input: 1000 3000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 324ms 2.4ms 1.9MB 317ms 0ms nim/clang 2.2.4
nim 2.nim 338ms 4.4ms 1.4MB 330ms 0ms nim 2.2.4
ocaml 1.ml 532ms 18ms 6.6MB 520ms 0ms ocaml 5.3.0
nim 1.nim timeout 0.0ms 1.3MB 4990ms 0ms nim 2.2.4
nim 1.nim timeout 0.0ms 1.5MB 4990ms 0ms nim/clang 2.2.4

Input: 100 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 48ms 0.2ms 1.5MB 40ms 0ms nim/clang 2.2.4
nim 2.nim 51ms 1.6ms 1.3MB 40ms 0ms nim 2.2.4
ocaml 1.ml 78ms 0.4ms 6.2MB 70ms 0ms ocaml 5.3.0
nim 1.nim 476ms 2.4ms 1.3MB 467ms 0ms nim 2.2.4
nim 1.nim 479ms 9.7ms 1.5MB 470ms 0ms nim/clang 2.2.4

merkletrees

Input: 17

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 547ms 6.1ms 33.9MB 527ms 3ms nim 2.2.4
nim 1.nim 645ms 20ms 34.7MB 623ms 7ms nim/clang 2.2.4
ocaml 1.ml 1077ms 22ms 70.2MB 1037ms 27ms ocaml 5.3.0
ocaml 2.ml 2068ms 35ms 91.8MB 2017ms 37ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 116ms 3.2ms 9.6MB 103ms 0ms nim 2.2.4
nim 1.nim 136ms 5.6ms 9.9MB 123ms 0ms nim/clang 2.2.4
ocaml 1.ml 144ms 1.4ms 21.7MB 127ms 3ms ocaml 5.3.0
ocaml 2.ml 359ms 6.4ms 27.7MB 340ms 7ms ocaml 5.3.0

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 320ms 1.7ms 1.8MB 310ms 0ms nim 2.2.4
nim 2.nim 343ms 3.6ms 2.0MB 337ms 0ms nim/clang 2.2.4
ocaml 1.ml 374ms 2.6ms 5.2MB 367ms 0ms ocaml 5.3.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 2.nim 35ms 0.8ms 1.8MB 30ms 0ms nim 2.2.4
nim 2.nim 36ms 0.6ms 2.0MB 30ms 0ms nim/clang 2.2.4
ocaml 1.ml 40ms 0.1ms 5.2MB 30ms 0ms ocaml 5.3.0

nsieve

Input: 12

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 271ms 4.0ms 41.5MB 263ms 0ms nim 2.2.4
nim 1.nim 322ms 6.8ms 41.8MB 313ms 0ms nim/clang 2.2.4
ocaml 1.ml 945ms 11ms 547.9MB 883ms 47ms ocaml 5.3.0
ocaml 2.ml 1884ms 7.1ms 17.2MB 1870ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 52ms 2.4ms 11.5MB 43ms 0ms nim 2.2.4
nim 1.nim 66ms 4.2ms 11.8MB 57ms 0ms nim/clang 2.2.4
ocaml 1.ml 178ms 0.8ms 142.3MB 153ms 10ms ocaml 5.3.0
ocaml 2.ml 464ms 1.5ms 9.3MB 453ms 0ms ocaml 5.3.0

regex-redux

Input: 2500000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 1646ms 10ms 152.3MB 1613ms 20ms nim/clang 2.2.4
nim 1.nim 1673ms 4.5ms 151.5MB 1643ms 13ms nim 2.2.4
ocaml 2.ml timeout 0.0ms 462.9MB 4830ms 157ms ocaml 5.3.0

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 173ms 2.5ms 17.5MB 160ms 0ms nim/clang 2.2.4
nim 1.nim 177ms 0.6ms 17.4MB 160ms 0ms nim 2.2.4
ocaml 2.ml 542ms 2.0ms 57.1MB 510ms 17ms ocaml 5.3.0

spectral-norm

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 3589ms 2.6ms 1.6MB 3580ms 0ms nim/clang 2.2.4
nim 1.nim 3610ms 3.4ms 1.4MB 3600ms 0ms nim 2.2.4
ocaml 2.ml 4558ms 6.5ms 6.3MB 4543ms 0ms ocaml 5.3.0

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 899ms 0.6ms 1.5MB 890ms 0ms nim/clang 2.2.4
nim 1.nim 904ms 3.3ms 1.3MB 893ms 0ms nim 2.2.4
ocaml 2.ml 1146ms 5.3ms 6.1MB 1137ms 0ms ocaml 5.3.0

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
nim 1.nim 226ms 0.2ms 1.5MB 220ms 0ms nim/clang 2.2.4
nim 1.nim 228ms 1.1ms 1.3MB 220ms 0ms nim 2.2.4
ocaml 2.ml 296ms 9.1ms 5.2MB 287ms 0ms ocaml 5.3.0