OCaml VS Crystal benchmarks

Current benchmark data was generated on Fri Aug 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 1231ms 8.3ms 64.2MB 1203ms 10ms crystal 1.17.0
ocaml 1.ml 3020ms 42ms 157.0MB 2927ms 77ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 104ms 1.6ms 11.0MB 90ms 0ms crystal 1.17.0
ocaml 1.ml 223ms 9.3ms 19.2MB 207ms 3ms 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 2510ms 4.1ms 2.9MB 2497ms 0ms crystal 1.17.0
ocaml 2.ml 2910ms 2.6ms 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 207ms 2.7ms 2.9MB 200ms 0ms crystal 1.17.0
ocaml 2.ml 244ms 0.9ms 4.9MB 230ms 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 1.8ms 24.8MB 333ms 0ms ocaml 5.3.0
crystal 2.cr 540ms 2.0ms 3.6MB 450ms 77ms crystal 1.17.0
crystal 1.cr 681ms 2.0ms 14.6MB 570ms 97ms crystal 1.17.0

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 6.ml 39ms 0.4ms 7.3MB 30ms 0ms ocaml 5.3.0
crystal 2.cr 57ms 0.8ms 3.6MB 40ms 0ms crystal 1.17.0
crystal 1.cr 72ms 0.8ms 4.4MB 53ms 7ms crystal 1.17.0

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 1.ml 1.8ms 0.1ms 5.1MB 0ms 0ms ocaml 5.3.0
crystal 1.cr 1.9ms 0.1ms 2.9MB 0ms 0ms crystal 1.17.0

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 37ms 0.9ms 3.0MB 30ms 0ms crystal 1.17.0
crystal 1.cr 70ms 1.9ms 3.0MB 60ms 0ms crystal 1.17.0
ocaml 1.ml 187ms 2.5ms 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 105ms 1.9ms 3.0MB 97ms 0ms crystal 1.17.0
crystal 1.cr 201ms 2.2ms 3.0MB 190ms 0ms crystal 1.17.0
ocaml 1.ml 537ms 13ms 6.6MB 523ms 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 1.2ms 3.0MB 10ms 0ms crystal 1.17.0
crystal 1.cr 33ms 1.2ms 3.0MB 20ms 0ms crystal 1.17.0
ocaml 1.ml 75ms 0.2ms 5.9MB 67ms 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 838ms 12ms 64.2MB 820ms 7ms crystal 1.17.0
ocaml 1.ml 1113ms 16ms 70.2MB 1073ms 27ms ocaml 5.3.0
ocaml 2.ml 2055ms 6.7ms 91.8MB 2000ms 40ms ocaml 5.3.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
ocaml 1.ml 146ms 2.9ms 21.7MB 130ms 7ms ocaml 5.3.0
crystal 1.cr 177ms 4.2ms 22.3MB 160ms 0ms crystal 1.17.0
ocaml 2.ml 358ms 7.5ms 27.6MB 340ms 3ms ocaml 5.3.0

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 345ms 2.9ms 3.4MB 337ms 0ms crystal 1.17.0
crystal 1.cr 346ms 3.1ms 3.4MB 337ms 0ms crystal 1.17.0
ocaml 1.ml 373ms 2.9ms 5.2MB 363ms 0ms ocaml 5.3.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 37ms 0.5ms 3.4MB 30ms 0ms crystal 1.17.0
crystal 1.cr 39ms 0.1ms 3.4MB 30ms 0ms crystal 1.17.0
ocaml 1.ml 42ms 0.9ms 5.3MB 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 301ms 3.1ms 8.3MB 290ms 0ms crystal 1.17.0
crystal 1.cr 420ms 4.6ms 43.0MB 403ms 0ms crystal 1.17.0
ocaml 1.ml 932ms 21ms 543.2MB 877ms 43ms ocaml 5.3.0
ocaml 2.ml 1887ms 12ms 19.0MB 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 74ms 0.2ms 4.5MB 70ms 0ms crystal 1.17.0
crystal 1.cr 89ms 0.6ms 13.2MB 80ms 0ms crystal 1.17.0
ocaml 1.ml 175ms 1.5ms 142.1MB 150ms 10ms ocaml 5.3.0
ocaml 2.ml 469ms 6.0ms 9.1MB 457ms 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 462.8MB 4823ms 167ms 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 3.2ms 57.1MB 510ms 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 3758ms 11ms 4.5MB 3750ms 0ms crystal 1.17.0
ocaml 2.ml 4574ms 4.7ms 6.4MB 4563ms 0ms ocaml 5.3.0

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 941ms 1.2ms 4.5MB 930ms 0ms crystal 1.17.0
ocaml 2.ml 1166ms 5.8ms 5.9MB 1153ms 0ms ocaml 5.3.0

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 242ms 3.7ms 3.9MB 233ms 0ms crystal 1.17.0
ocaml 2.ml 295ms 3.8ms 5.2MB 283ms 0ms ocaml 5.3.0