OCaml VS Crystal benchmarks

Current benchmark data was generated on Tue Jul 01 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 1302ms 4.1ms 64.2MB 1273ms 17ms crystal 1.16.3
ocaml 1.ml 3177ms 13ms 157.2MB 3097ms 63ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 109ms 2.8ms 11.0MB 100ms 0ms crystal 1.16.3
ocaml 1.ml 234ms 3.5ms 19.2MB 217ms 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 2487ms 23ms 2.9MB 2473ms 0ms crystal 1.16.3
ocaml 2.ml 2910ms 4.7ms 4.9MB 2900ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 205ms 3.6ms 2.9MB 197ms 0ms crystal 1.16.3
ocaml 2.ml 245ms 1.0ms 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 348ms 0.3ms 24.8MB 337ms 0ms ocaml 5.3.0
crystal 2.cr 535ms 2.4ms 3.5MB 450ms 70ms crystal 1.16.3
crystal 1.cr 681ms 3.2ms 14.6MB 570ms 97ms crystal 1.16.3

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 6.ml 39ms 0.9ms 7.6MB 30ms 0ms ocaml 5.3.0
crystal 2.cr 58ms 1.8ms 3.6MB 40ms 7ms crystal 1.16.3
crystal 1.cr 72ms 0.7ms 4.9MB 53ms 7ms 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 5.1MB 0ms 0ms ocaml 5.3.0
crystal 1.cr 2.0ms 0.1ms 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 0.7ms 3.0MB 30ms 0ms crystal 1.16.3
crystal 1.cr 65ms 1.5ms 3.0MB 57ms 0ms crystal 1.16.3
ocaml 1.ml 180ms 10ms 6.4MB 170ms 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 102ms 0.4ms 3.0MB 90ms 0ms crystal 1.16.3
crystal 1.cr 189ms 6.6ms 3.0MB 177ms 0ms crystal 1.16.3
ocaml 1.ml 537ms 22ms 6.6MB 527ms 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 18ms 0.7ms 3.0MB 10ms 0ms crystal 1.16.3
crystal 1.cr 30ms 1.5ms 3.0MB 20ms 0ms crystal 1.16.3
ocaml 1.ml 77ms 0.7ms 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 867ms 21ms 64.2MB 843ms 10ms crystal 1.16.3
ocaml 1.ml 1078ms 7.3ms 70.2MB 1040ms 27ms ocaml 5.3.0
ocaml 2.ml 2068ms 16ms 91.7MB 2013ms 40ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 1.ml 145ms 3.7ms 21.7MB 130ms 0ms ocaml 5.3.0
crystal 1.cr 174ms 3.9ms 22.3MB 157ms 0ms crystal 1.16.3
ocaml 2.ml 361ms 9.3ms 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
crystal 2.cr 342ms 2.4ms 3.3MB 333ms 0ms crystal 1.16.3
crystal 1.cr 350ms 6.8ms 3.4MB 343ms 0ms crystal 1.16.3
ocaml 1.ml 375ms 3.2ms 5.3MB 363ms 0ms ocaml 5.3.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 38ms 1.2ms 3.3MB 30ms 0ms crystal 1.16.3
crystal 2.cr 38ms 0.4ms 3.4MB 30ms 0ms crystal 1.16.3
ocaml 1.ml 41ms 1.9ms 5.2MB 33ms 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 348ms 2.9ms 8.3MB 337ms 0ms crystal 1.16.3
crystal 1.cr 422ms 6.9ms 43.0MB 413ms 0ms crystal 1.16.3
ocaml 1.ml 949ms 8.7ms 543.2MB 887ms 47ms ocaml 5.3.0
ocaml 2.ml 1888ms 14ms 17.7MB 1877ms 0ms ocaml 5.3.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 87ms 1.4ms 4.5MB 80ms 0ms crystal 1.16.3
crystal 1.cr 90ms 3.2ms 13.2MB 83ms 0ms crystal 1.16.3
ocaml 1.ml 179ms 2.9ms 142.3MB 157ms 10ms ocaml 5.3.0
ocaml 2.ml 466ms 5.7ms 9.1MB 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
ocaml 2.ml timeout 0.0ms 463.0MB 4823ms 163ms ocaml 5.3.0

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 2.ml 552ms 6.9ms 57.1MB 520ms 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 3763ms 15ms 4.6MB 3753ms 0ms crystal 1.16.3
ocaml 2.ml 4567ms 4.6ms 6.4MB 4553ms 0ms ocaml 5.3.0

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 946ms 8.1ms 4.4MB 933ms 0ms crystal 1.16.3
ocaml 2.ml 1145ms 4.4ms 6.1MB 1137ms 0ms ocaml 5.3.0

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 244ms 2.8ms 3.9MB 237ms 0ms crystal 1.16.3
ocaml 2.ml 291ms 2.2ms 5.2MB 283ms 0ms ocaml 5.3.0