Swift VS Kotlin 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
kotlin 1.kt 502ms 0.9ms 575.9MB 597ms 100ms kotlin/jvm 21
swift 1.swift 2692ms 22ms 53.8MB 2657ms 20ms swift 6.1.2
kotlin 1.kt 4076ms 141ms 134.1MB 4270ms 63ms kotlin/native 2.1.20

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 122ms 1.3ms 159.4MB 143ms 30ms kotlin/jvm 21
kotlin 1.kt 232ms 38ms 17.6MB 243ms 3ms kotlin/native 2.1.20
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

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
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

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

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 2.2ms 0.1ms 3.0MB 0ms 0ms kotlin/native 2.1.20
swift 1.swift 2.4ms 0.1ms 5.6MB 0ms 0ms swift 6.1.2
kotlin 1.kt 62ms 0.6ms 47.7MB 74ms 18ms kotlin/jvm 21

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
swift 7.swift 346ms 2.1ms 9.9MB 337ms 0ms swift 6.1.2
kotlin 1n.kt 354ms 5.0ms 3.6MB 343ms 0ms kotlin/native 2.1.20
kotlin 1.kt 443ms 0.3ms 49.2MB 487ms 13ms kotlin/jvm 21

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1n.kt 39ms 1.6ms 3.6MB 30ms 0ms kotlin/native 2.1.20
swift 7.swift 39ms 0.9ms 9.9MB 30ms 0ms swift 6.1.2
kotlin 1-m.kt 119ms 1.7ms 49.5MB 170ms 13ms kotlin/jvm 21

pidigits

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 3757ms 42ms 354.4MB 4560ms 113ms kotlin/jvm 21
kotlin 1n.kt timeout 0.0ms 26.6MB 3957ms 1507ms kotlin/native 2.1.20
kotlin 2n.kt timeout 0.0ms 30.6MB 5110ms 133ms kotlin/native 2.1.20
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
kotlin 1-m.kt 990ms 32ms 353.0MB 1737ms 93ms kotlin/jvm 21
swift 1.swift 1865ms 11ms 7.0MB 1853ms 0ms swift 6.1.2
kotlin 1n.kt timeout 0.0ms 26.3MB 3987ms 1517ms kotlin/native 2.1.20
kotlin 2n.kt timeout 0.0ms 30.9MB 5117ms 123ms kotlin/native 2.1.20