OCaml VS Rust 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
rust 4.rs 1316ms 18ms 33.6MB 1293ms 10ms rustc 1.88.0
rust 5.rs 1480ms 41ms 33.8MB 1457ms 7ms rustc 1.88.0
rust 3.rs 1534ms 41ms 49.8MB 1507ms 17ms rustc 1.88.0
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
rust 4.rs 123ms 1.4ms 5.6MB 110ms 0ms rustc 1.88.0
rust 5.rs 126ms 1.2ms 5.8MB 117ms 0ms rustc 1.88.0
rust 3.rs 135ms 4.9ms 7.8MB 123ms 0ms rustc 1.88.0
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
rust 3-im.rs 411ms 5.2ms 2.0MB 1570ms 0ms rustc 1.88.0
rust 5-m.rs 551ms 4.1ms 2.0MB 2133ms 0ms rustc 1.88.0
rust 2-im.rs 672ms 14ms 2.1MB 2573ms 0ms rustc 1.88.0
rust 1-m.rs 940ms 12ms 2.0MB 3637ms 0ms rustc 1.88.0
rust 3-i.rs 1508ms 1.0ms 1.9MB 1500ms 0ms rustc 1.88.0
rust 2-i.rs 2416ms 18ms 1.8MB 2407ms 0ms rustc 1.88.0
rust 1.rs 2785ms 14ms 1.8MB 2773ms 0ms rustc 1.88.0
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
rust 3-im.rs 38ms 0.1ms 2.0MB 120ms 0ms rustc 1.88.0
rust 5-m.rs 53ms 0.8ms 2.1MB 170ms 0ms rustc 1.88.0
rust 2-im.rs 62ms 0.1ms 2.0MB 203ms 0ms rustc 1.88.0
rust 1-m.rs 84ms 1.5ms 2.1MB 290ms 0ms rustc 1.88.0
rust 3-i.rs 126ms 0.3ms 1.9MB 120ms 0ms rustc 1.88.0
rust 2-i.rs 198ms 0.3ms 1.8MB 190ms 0ms rustc 1.88.0
rust 1.rs 229ms 3.3ms 1.8MB 223ms 0ms rustc 1.88.0
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
rust 6.rs 88ms 1.4ms 1.9MB 80ms 0ms rustc 1.88.0
rust 5c-m.rs 90ms 0.0ms 3.4MB 260ms 0ms rustc 1.88.0
rust 5-m.rs 93ms 0.3ms 3.2MB 287ms 0ms rustc 1.88.0
rust 1c.rs 163ms 1.1ms 1.9MB 153ms 0ms rustc 1.88.0
rust 1.rs 196ms 1.1ms 1.9MB 187ms 0ms rustc 1.88.0
ocaml 6.ml 348ms 0.3ms 24.8MB 337ms 0ms ocaml 5.3.0

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
rust 6.rs 12ms 1.3ms 1.9MB 10ms 0ms rustc 1.88.0
rust 5-m.rs 16ms 0.4ms 3.2MB 27ms 0ms rustc 1.88.0
rust 5c-m.rs 17ms 0.2ms 3.2MB 23ms 0ms rustc 1.88.0
rust 1c.rs 18ms 0.2ms 1.9MB 10ms 0ms rustc 1.88.0
rust 1.rs 22ms 0.1ms 1.9MB 13ms 0ms rustc 1.88.0
ocaml 6.ml 39ms 0.9ms 7.6MB 30ms 0ms ocaml 5.3.0

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
rust 1.rs 1.2ms 0.1ms 1.8MB 0ms 0ms rustc 1.88.0
rust 1.rs 1.2ms 0.0ms 1.9MB 0ms 0ms rustc 1.90.0-nightly
ocaml 1.ml 1.8ms 0.2ms 5.1MB 0ms 0ms ocaml 5.3.0

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
rust 0-unsafe.rs 36ms 6.0ms 1.8MB 27ms 0ms rustc 1.88.0
rust 1.rs 50ms 10ms 1.9MB 40ms 0ms rustc 1.88.0
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
rust 0-unsafe.rs 145ms 6.3ms 1.8MB 137ms 0ms rustc 1.88.0
rust 1.rs 212ms 32ms 1.9MB 203ms 0ms rustc 1.88.0
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
rust 0-unsafe.rs 24ms 0.4ms 1.8MB 20ms 0ms rustc 1.88.0
rust 1.rs 30ms 0.9ms 1.8MB 20ms 0ms rustc 1.88.0
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
rust 1.rs 720ms 21ms 33.8MB 697ms 10ms rustc 1.88.0
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
rust 1.rs 154ms 3.2ms 9.8MB 143ms 0ms rustc 1.88.0
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
rust 4-i.rs 164ms 0.2ms 1.8MB 160ms 0ms rustc 1.88.0
rust 7-i.rs 219ms 1.1ms 1.8MB 210ms 0ms rustc 1.88.0
rust 1.rs 229ms 0.5ms 1.8MB 220ms 0ms rustc 1.88.0
rust 3.rs 279ms 0.7ms 1.9MB 270ms 0ms rustc 1.90.0-nightly
rust 2.rs 279ms 0.5ms 1.6MB 270ms 0ms rustc 1.88.0
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
rust 4-i.rs 18ms 0.1ms 1.8MB 10ms 0ms rustc 1.88.0
rust 7-i.rs 24ms 0.5ms 1.8MB 20ms 0ms rustc 1.88.0
rust 1.rs 25ms 0.4ms 1.8MB 20ms 0ms rustc 1.88.0
rust 2.rs 30ms 0.2ms 1.8MB 20ms 0ms rustc 1.88.0
rust 3.rs 30ms 0.1ms 1.8MB 20ms 0ms rustc 1.90.0-nightly
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
rust 2.rs 304ms 3.2ms 6.6MB 293ms 0ms rustc 1.88.0
rust 1.rs 327ms 7.2ms 40.9MB 313ms 0ms rustc 1.88.0
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
rust 1.rs 59ms 2.3ms 11.6MB 50ms 0ms rustc 1.88.0
rust 2.rs 78ms 1.2ms 2.9MB 70ms 0ms rustc 1.88.0
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
rust 7.rs 454ms 7.3ms 78.4MB 463ms 17ms rustc 1.88.0
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
rust 7.rs 64ms 5.1ms 11.6MB 57ms 3ms rustc 1.88.0
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
rust 8-m.rs 493ms 0.8ms 2.5MB 1907ms 3ms rustc 1.90.0-nightly
rust 7-m.rs 493ms 0.4ms 2.1MB 1910ms 0ms rustc 1.88.0
rust 8.rs 994ms 2.7ms 2.4MB 983ms 0ms rustc 1.90.0-nightly
rust 7.rs 1927ms 5.1ms 1.9MB 1917ms 0ms rustc 1.88.0
rust 2-m.rs 2073ms 4.7ms 2.4MB 8130ms 10ms rustc 1.88.0
rust 2.rs 4274ms 5.2ms 2.0MB 4267ms 0ms rustc 1.88.0
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
rust 8-m.rs 127ms 0.4ms 2.3MB 467ms 3ms rustc 1.90.0-nightly
rust 7-m.rs 128ms 0.8ms 2.3MB 467ms 0ms rustc 1.88.0
rust 8.rs 251ms 0.7ms 2.1MB 240ms 0ms rustc 1.90.0-nightly
rust 7.rs 491ms 1.9ms 1.8MB 480ms 0ms rustc 1.88.0
rust 2-m.rs 521ms 0.5ms 2.1MB 2023ms 3ms rustc 1.88.0
rust 2.rs 1070ms 2.2ms 1.9MB 1060ms 0ms rustc 1.88.0
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
rust 8-m.rs 36ms 0.4ms 2.1MB 110ms 3ms rustc 1.90.0-nightly
rust 7-m.rs 36ms 0.4ms 2.0MB 110ms 0ms rustc 1.88.0
rust 8.rs 65ms 0.9ms 2.0MB 60ms 0ms rustc 1.90.0-nightly
rust 7.rs 125ms 1.8ms 1.8MB 120ms 0ms rustc 1.88.0
rust 2-m.rs 134ms 0.5ms 2.1MB 497ms 0ms rustc 1.88.0
rust 2.rs 270ms 1.5ms 1.9MB 260ms 0ms rustc 1.88.0
ocaml 2.ml 291ms 2.2ms 5.2MB 283ms 0ms ocaml 5.3.0