OCaml VS Rust 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
rust 4.rs 1259ms 3.4ms 33.8MB 1240ms 7ms rustc 1.88.0
rust 5.rs 1337ms 1.1ms 33.8MB 1317ms 10ms rustc 1.88.0
rust 3.rs 1443ms 32ms 49.8MB 1410ms 13ms rustc 1.88.0
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
rust 4.rs 121ms 2.1ms 5.8MB 110ms 0ms rustc 1.88.0
rust 5.rs 126ms 2.0ms 5.8MB 120ms 0ms rustc 1.88.0
rust 3.rs 138ms 4.5ms 7.8MB 127ms 0ms rustc 1.88.0
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
rust 3-im.rs 413ms 0.7ms 2.1MB 1587ms 0ms rustc 1.88.0
rust 5-m.rs 558ms 2.0ms 2.0MB 2130ms 0ms rustc 1.88.0
rust 2-im.rs 667ms 5.0ms 2.1MB 2540ms 0ms rustc 1.88.0
rust 1-m.rs 955ms 4.2ms 2.1MB 3670ms 0ms rustc 1.88.0
rust 3-i.rs 1497ms 2.0ms 1.8MB 1490ms 0ms rustc 1.88.0
rust 2-i.rs 2365ms 0.5ms 1.8MB 2357ms 0ms rustc 1.88.0
rust 1.rs 2700ms 26ms 1.8MB 2690ms 0ms rustc 1.88.0
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
rust 3-im.rs 38ms 0.1ms 2.0MB 127ms 0ms rustc 1.88.0
rust 5-m.rs 52ms 1.3ms 2.1MB 170ms 0ms rustc 1.88.0
rust 2-im.rs 60ms 1.6ms 2.0MB 200ms 0ms rustc 1.88.0
rust 1-m.rs 84ms 0.3ms 2.0MB 290ms 0ms rustc 1.88.0
rust 3-i.rs 125ms 0.6ms 1.9MB 120ms 0ms rustc 1.88.0
rust 2-i.rs 195ms 0.4ms 1.8MB 183ms 0ms rustc 1.88.0
rust 1.rs 224ms 3.0ms 1.8MB 217ms 0ms rustc 1.88.0
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
rust 6.rs 88ms 2.0ms 1.9MB 80ms 0ms rustc 1.88.0
rust 5c-m.rs 89ms 0.8ms 3.2MB 250ms 0ms rustc 1.88.0
rust 5-m.rs 92ms 1.4ms 3.2MB 287ms 0ms rustc 1.88.0
rust 1c.rs 164ms 0.4ms 1.9MB 157ms 0ms rustc 1.88.0
rust 1.rs 197ms 1.0ms 1.9MB 190ms 0ms rustc 1.88.0
ocaml 6.ml 346ms 1.8ms 24.8MB 333ms 0ms ocaml 5.3.0

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
rust 6.rs 11ms 1.0ms 1.9MB 10ms 0ms rustc 1.88.0
rust 5c-m.rs 15ms 0.3ms 3.4MB 23ms 0ms rustc 1.88.0
rust 5-m.rs 16ms 0.7ms 3.4MB 27ms 0ms rustc 1.88.0
rust 1c.rs 19ms 0.5ms 1.9MB 10ms 0ms rustc 1.88.0
rust 1.rs 22ms 0.4ms 1.9MB 10ms 0ms rustc 1.88.0
ocaml 6.ml 39ms 0.4ms 7.3MB 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 0.1ms 1.9MB 0ms 0ms rustc 1.90.0-nightly
ocaml 1.ml 1.8ms 0.1ms 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 37ms 4.5ms 1.9MB 27ms 0ms rustc 1.88.0
rust 1.rs 51ms 3.1ms 2.0MB 43ms 0ms rustc 1.88.0
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
rust 0-unsafe.rs 133ms 9.5ms 1.8MB 123ms 0ms rustc 1.88.0
rust 1.rs 203ms 10ms 1.9MB 193ms 0ms rustc 1.88.0
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
rust 0-unsafe.rs 24ms 0.7ms 1.8MB 17ms 0ms rustc 1.88.0
rust 1.rs 31ms 1.7ms 1.9MB 20ms 0ms rustc 1.88.0
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
rust 1.rs 709ms 8.0ms 33.8MB 690ms 10ms rustc 1.88.0
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
rust 1.rs 160ms 6.9ms 9.9MB 150ms 0ms rustc 1.88.0
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
rust 4-i.rs 163ms 0.3ms 1.8MB 157ms 0ms rustc 1.88.0
rust 7-i.rs 218ms 1.1ms 1.8MB 210ms 0ms rustc 1.88.0
rust 1.rs 229ms 0.6ms 1.8MB 220ms 0ms rustc 1.88.0
rust 3.rs 279ms 0.5ms 1.9MB 270ms 0ms rustc 1.90.0-nightly
rust 2.rs 279ms 0.3ms 1.6MB 270ms 0ms rustc 1.88.0
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
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 0.5ms 1.8MB 20ms 0ms rustc 1.88.0
rust 3.rs 30ms 0.1ms 1.9MB 20ms 0ms rustc 1.90.0-nightly
rust 2.rs 30ms 0.1ms 1.6MB 20ms 0ms rustc 1.88.0
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
rust 2.rs 301ms 2.9ms 6.6MB 290ms 0ms rustc 1.88.0
rust 1.rs 305ms 4.3ms 40.9MB 287ms 3ms rustc 1.88.0
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
rust 1.rs 64ms 1.9ms 11.6MB 57ms 0ms rustc 1.88.0
rust 2.rs 77ms 1.1ms 2.9MB 70ms 0ms rustc 1.88.0
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
rust 7.rs 438ms 2.7ms 78.6MB 450ms 13ms rustc 1.88.0
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
rust 7.rs 49ms 0.5ms 11.6MB 40ms 0ms rustc 1.88.0
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
rust 7-m.rs 492ms 0.6ms 2.3MB 1907ms 3ms rustc 1.88.0
rust 8-m.rs 493ms 0.0ms 2.4MB 1917ms 0ms rustc 1.90.0-nightly
rust 8.rs 994ms 2.5ms 2.4MB 983ms 0ms rustc 1.90.0-nightly
rust 7.rs 1964ms 9.9ms 2.0MB 1957ms 0ms rustc 1.88.0
rust 2-m.rs 2079ms 5.2ms 2.4MB 8167ms 3ms rustc 1.88.0
rust 2.rs 4264ms 2.5ms 2.0MB 4253ms 0ms rustc 1.88.0
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
rust 7-m.rs 127ms 0.2ms 2.1MB 463ms 0ms rustc 1.88.0
rust 8-m.rs 127ms 0.4ms 2.3MB 470ms 0ms rustc 1.90.0-nightly
rust 8.rs 251ms 0.9ms 2.0MB 240ms 0ms rustc 1.90.0-nightly
rust 7.rs 496ms 4.5ms 1.8MB 490ms 0ms rustc 1.88.0
rust 2-m.rs 523ms 1.6ms 2.3MB 2023ms 0ms rustc 1.88.0
rust 2.rs 1068ms 0.2ms 2.0MB 1060ms 0ms rustc 1.88.0
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
rust 8-m.rs 35ms 0.2ms 2.1MB 110ms 0ms rustc 1.90.0-nightly
rust 7-m.rs 35ms 0.4ms 2.1MB 110ms 0ms rustc 1.88.0
rust 8.rs 65ms 0.5ms 2.0MB 60ms 0ms rustc 1.90.0-nightly
rust 7.rs 130ms 7.3ms 1.8MB 123ms 0ms rustc 1.88.0
rust 2-m.rs 135ms 0.3ms 2.1MB 493ms 3ms rustc 1.88.0
rust 2.rs 269ms 0.8ms 1.9MB 260ms 0ms rustc 1.88.0
ocaml 2.ml 295ms 3.8ms 5.2MB 283ms 0ms ocaml 5.3.0