Programming Language and compiler
Benchmarks

OCaml VS Crystal benchmarks

Current benchmark data was generated on Mon Jun 23 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
crystal 1.cr 1282ms 30ms 64.2MB 1257ms 10ms crystal 1.16.3
ocaml 1.ml 3028ms 44ms 157.2MB 2940ms 73ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 109ms 0.7ms 11.0MB 97ms 0ms crystal 1.16.3
ocaml 1.ml 214ms 0.9ms 19.1MB 200ms 0ms ocaml 5.3.0

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 2481ms 9.0ms 2.9MB 2470ms 0ms crystal 1.16.3
ocaml 2.ml 2914ms 16ms 4.9MB 2907ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 213ms 7.6ms 2.9MB 200ms 0ms crystal 1.16.3
ocaml 2.ml 245ms 3.3ms 4.9MB 237ms 0ms ocaml 5.3.0

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 6.ml 347ms 1.7ms 24.8MB 337ms 0ms ocaml 5.3.0
crystal 2.cr 535ms 2.1ms 3.5MB 447ms 80ms crystal 1.16.3
crystal 1.cr 681ms 1.3ms 14.6MB 573ms 93ms crystal 1.16.3

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 6.ml 39ms 0.5ms 7.5MB 30ms 0ms ocaml 5.3.0
crystal 2.cr 57ms 0.7ms 3.6MB 40ms 0ms crystal 1.16.3
crystal 1.cr 73ms 0.9ms 4.9MB 57ms 3ms crystal 1.16.3

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 1.ml 1.8ms 0.2ms 5.0MB 0ms 0ms ocaml 5.3.0
crystal 1.cr 1.9ms 0.2ms 2.9MB 0ms 0ms crystal 1.16.3

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 36ms 0.9ms 3.0MB 30ms 0ms crystal 1.16.3
crystal 1.cr 65ms 1.9ms 3.0MB 60ms 0ms crystal 1.16.3
ocaml 1.ml 190ms 0.6ms 6.4MB 180ms 0ms ocaml 5.3.0

Input: 1000 3000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 101ms 2.3ms 3.0MB 93ms 0ms crystal 1.16.3
crystal 1.cr 186ms 0.8ms 3.0MB 180ms 0ms crystal 1.16.3
ocaml 1.ml 518ms 3.2ms 6.6MB 510ms 0ms ocaml 5.3.0

Input: 100 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 19ms 1.1ms 3.0MB 10ms 0ms crystal 1.16.3
crystal 1.cr 30ms 0.6ms 3.0MB 20ms 0ms crystal 1.16.3
ocaml 1.ml 77ms 1.4ms 5.9MB 70ms 0ms ocaml 5.3.0

merkletrees

Input: 17

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 880ms 16ms 64.2MB 857ms 10ms crystal 1.16.3
ocaml 1.ml 1094ms 11ms 70.2MB 1047ms 30ms ocaml 5.3.0
ocaml 2.ml 2066ms 16ms 91.8MB 2013ms 33ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 1.ml 147ms 4.1ms 21.7MB 130ms 7ms ocaml 5.3.0
crystal 1.cr 173ms 3.0ms 22.2MB 157ms 0ms crystal 1.16.3
ocaml 2.ml 367ms 7.6ms 27.7MB 343ms 7ms ocaml 5.3.0

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 342ms 1.3ms 3.3MB 330ms 0ms crystal 1.16.3
crystal 1.cr 344ms 2.9ms 3.3MB 333ms 0ms crystal 1.16.3
ocaml 1.ml 373ms 1.9ms 5.2MB 360ms 0ms ocaml 5.3.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 38ms 0.4ms 3.3MB 30ms 0ms crystal 1.16.3
crystal 1.cr 38ms 1.4ms 3.3MB 30ms 0ms crystal 1.16.3
ocaml 1.ml 41ms 1.4ms 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
crystal 2.cr 350ms 2.1ms 8.3MB 340ms 0ms crystal 1.16.3
crystal 1.cr 432ms 2.5ms 42.9MB 420ms 0ms crystal 1.16.3
ocaml 1.ml 957ms 3.4ms 550.3MB 900ms 43ms ocaml 5.3.0
ocaml 2.ml 1886ms 14ms 18.9MB 1873ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 89ms 2.4ms 4.5MB 80ms 0ms crystal 1.16.3
crystal 1.cr 92ms 3.7ms 13.2MB 83ms 0ms crystal 1.16.3
ocaml 1.ml 191ms 3.0ms 141.6MB 170ms 10ms ocaml 5.3.0
ocaml 2.ml 471ms 4.3ms 9.1MB 460ms 0ms ocaml 5.3.0

regex-redux

Input: 2500000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 2.ml timeout 0.0ms 462.9MB 4830ms 153ms ocaml 5.3.0

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 2.ml 549ms 4.5ms 57.1MB 513ms 23ms ocaml 5.3.0

spectral-norm

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 3760ms 10ms 4.5MB 3747ms 0ms crystal 1.16.3
ocaml 2.ml 4582ms 24ms 6.4MB 4570ms 0ms ocaml 5.3.0

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 949ms 7.6ms 4.4MB 940ms 0ms crystal 1.16.3
ocaml 2.ml 1159ms 5.5ms 6.1MB 1150ms 0ms ocaml 5.3.0

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 241ms 5.4ms 3.8MB 233ms 0ms crystal 1.16.3
ocaml 2.ml 294ms 4.6ms 5.2MB 283ms 0ms ocaml 5.3.0