Programming Language and compiler
Benchmarks

OCaml VS Crystal 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
crystal 1.cr 1241ms 14ms 64.2MB 1213ms 13ms crystal 1.16.3
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
crystal 1.cr 105ms 3.7ms 11.0MB 93ms 0ms crystal 1.16.3
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
crystal 1.cr 2476ms 14ms 2.9MB 2467ms 0ms crystal 1.16.3
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
crystal 1.cr 205ms 3.2ms 2.9MB 197ms 0ms crystal 1.16.3
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
ocaml 6.ml 346ms 1.9ms 24.8MB 330ms 0ms ocaml 5.3.0
crystal 2.cr 534ms 3.4ms 3.6MB 443ms 73ms crystal 1.16.3
crystal 1.cr 676ms 1.2ms 14.6MB 570ms 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 0.7ms 7.4MB 30ms 0ms ocaml 5.3.0
crystal 2.cr 57ms 1.2ms 3.5MB 40ms 3ms crystal 1.16.3
crystal 1.cr 73ms 2.0ms 4.4MB 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 0.1ms 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 35ms 0.6ms 3.0MB 30ms 0ms crystal 1.16.3
crystal 1.cr 65ms 0.7ms 3.0MB 60ms 0ms crystal 1.16.3
ocaml 1.ml 173ms 2.7ms 6.4MB 163ms 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 1.8ms 3.0MB 90ms 0ms crystal 1.16.3
crystal 1.cr 186ms 0.4ms 3.0MB 180ms 0ms crystal 1.16.3
ocaml 1.ml 532ms 18ms 6.6MB 520ms 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 1.1ms 3.0MB 20ms 0ms crystal 1.16.3
ocaml 1.ml 78ms 0.4ms 6.2MB 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 843ms 9.4ms 64.2MB 820ms 10ms crystal 1.16.3
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
ocaml 1.ml 144ms 1.4ms 21.7MB 127ms 3ms ocaml 5.3.0
crystal 1.cr 178ms 3.9ms 22.2MB 163ms 0ms crystal 1.16.3
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
crystal 2.cr 343ms 3.1ms 3.3MB 333ms 0ms crystal 1.16.3
crystal 1.cr 347ms 1.5ms 3.3MB 337ms 0ms crystal 1.16.3
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
crystal 1.cr 37ms 0.6ms 3.3MB 30ms 0ms crystal 1.16.3
crystal 2.cr 38ms 0.9ms 3.3MB 30ms 0ms crystal 1.16.3
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
crystal 2.cr 351ms 3.7ms 8.3MB 340ms 0ms crystal 1.16.3
crystal 1.cr 418ms 6.0ms 43.0MB 407ms 0ms crystal 1.16.3
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
crystal 2.cr 87ms 1.6ms 4.5MB 80ms 0ms crystal 1.16.3
crystal 1.cr 92ms 2.2ms 13.1MB 80ms 0ms crystal 1.16.3
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
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
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
crystal 1.cr 3757ms 13ms 4.5MB 3747ms 0ms crystal 1.16.3
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
crystal 1.cr 948ms 9.2ms 4.4MB 937ms 0ms crystal 1.16.3
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
crystal 1.cr 238ms 1.0ms 3.9MB 230ms 0ms crystal 1.16.3
ocaml 2.ml 296ms 9.1ms 5.2MB 287ms 0ms ocaml 5.3.0