Programming Language and compiler
Benchmarks

Swift 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
swift 1.swift 2692ms 22ms 53.8MB 2657ms 20ms swift 6.1.2

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
swift 1.swift 240ms 0.7ms 11.9MB 230ms 0ms swift 6.1.2

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
swift 1.swift 2463ms 7.5ms 5.5MB 2453ms 0ms swift 6.1.2
crystal 1.cr 2476ms 14ms 2.9MB 2467ms 0ms crystal 1.16.3

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
swift 1.swift 213ms 2.3ms 5.5MB 200ms 0ms swift 6.1.2

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
swift 3-m.swift 139ms 1.6ms 20.7MB 400ms 3ms swift 6.1.2
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
swift 3.swift 37ms 0.3ms 14.2MB 30ms 0ms swift 6.1.2
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
crystal 1.cr 1.9ms 0.2ms 2.9MB 0ms 0ms crystal 1.16.3
swift 1.swift 2.4ms 0.1ms 5.6MB 0ms 0ms swift 6.1.2

knucleotide

Input: 2500000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
swift 2-m.swift 1361ms 16ms 74.3MB 4960ms 37ms swift 6.1.2

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
swift 2-m.swift 251ms 2.0ms 60.0MB 663ms 30ms swift 6.1.2

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
swift 7.swift 346ms 2.1ms 9.9MB 337ms 0ms swift 6.1.2
crystal 1.cr 347ms 1.5ms 3.3MB 337ms 0ms crystal 1.16.3

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
swift 7.swift 39ms 0.9ms 9.9MB 30ms 0ms swift 6.1.2

pidigits

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 1967ms 53ms 6.3MB 1943ms 13ms crystal 1.16.3
swift 1.swift timeout 0.0ms 7.3MB 4927ms 60ms swift 6.1.2

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 446ms 6.4ms 5.0MB 433ms 0ms crystal 1.16.3
swift 1.swift 1865ms 11ms 7.0MB 1853ms 0ms swift 6.1.2