Kotlin VS C# 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
kotlin 1.kt 488ms 8.7ms 575.8MB 583ms 93ms kotlin/jvm 21
csharp 1.cs 987ms 1.3ms 197.6MB 1000ms 140ms dotnet 9.0.301
csharp 1.cs 1008ms 13ms 179.9MB 1017ms 137ms dotnet/aot 9.0.301
csharp 1.cs 1685ms 31ms 103.5MB 1857ms 217ms mono 6.12.0
kotlin 1.kt 3941ms 160ms 145.0MB 4120ms 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 121ms 2.9ms 159.3MB 143ms 33ms kotlin/jvm 21
csharp 1.cs 122ms 5.7ms 36.6MB 90ms 30ms dotnet/aot 9.0.301
csharp 1.cs 142ms 0.8ms 41.9MB 120ms 13ms mono 6.12.0
csharp 1.cs 203ms 6.4ms 50.0MB 157ms 33ms dotnet 9.0.301
kotlin 1.kt 210ms 3.5ms 17.7MB 217ms 7ms kotlin/native 2.1.20

coro-prime-sieve

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 2-m.kt 2049ms 224ms 241.0MB 7630ms 117ms kotlin/jvm 21
kotlin 1.kt 2241ms 54ms 220.1MB 3060ms 77ms kotlin/jvm 21
csharp 1-m.cs 2289ms 142ms 50.7MB 8040ms 73ms dotnet/aot 9.0.301
csharp 1-m.cs 2934ms 143ms 73.2MB 10080ms 107ms dotnet 9.0.301
kotlin 2-m.kt 4233ms 52ms 21.4MB 14190ms 543ms kotlin/native 2.1.20
kotlin 1.kt timeout 0.0ms 17.4MB 5510ms 20ms kotlin/native 2.1.20

Input: 1000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 1-m.cs 150ms 2.1ms 18.5MB 430ms 7ms dotnet/aot 9.0.301
kotlin 2-m.kt 248ms 6.0ms 21.0MB 830ms 43ms kotlin/native 2.1.20
csharp 1-m.cs 290ms 28ms 40.0MB 830ms 27ms dotnet 9.0.301
kotlin 1.kt 388ms 5.4ms 17.4MB 397ms 7ms kotlin/native 2.1.20
kotlin 1-m.kt 485ms 16ms 75.0MB 1087ms 43ms kotlin/jvm 21
kotlin 2-m.kt 854ms 53ms 101.2MB 2957ms 77ms kotlin/jvm 21

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
csharp 1.cs 6.3ms 0.3ms 8.3MB 0ms 0ms dotnet/aot 9.0.301
csharp 1.cs 32ms 1.0ms 21.2MB 20ms 0ms mono 6.12.0
csharp 1.cs 38ms 1.2ms 26.3MB 20ms 4ms dotnet 9.0.301
kotlin 1.kt 65ms 2.5ms 47.7MB 76ms 16ms kotlin/jvm 21

http-server

Input: 3000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2-http2.cs 552ms 7.6ms 108.9MB 773ms 150ms dotnet 9.0.301
csharp 2-m.cs 625ms 6.3ms 147.0MB 797ms 533ms dotnet 9.0.301
csharp 2-http3.cs 717ms 3.8ms 145.7MB 1173ms 253ms dotnet 9.0.301
csharp 1-m.cs 756ms 9.5ms 170.9MB 1177ms 713ms dotnet 9.0.301
kotlin 2-m.kt 3271ms 1443ms 346.3MB 5647ms 970ms kotlin/jvm 21
kotlin 1.kt timeout 0.0ms 402.2MB 16220ms 2767ms kotlin/jvm 21

Input: 500

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2-m.cs 376ms 9.3ms 87.8MB 420ms 190ms dotnet 9.0.301
csharp 1-m.cs 415ms 12ms 98.2MB 577ms 220ms dotnet 9.0.301
csharp 2-http2.cs 474ms 3.3ms 86.0MB 540ms 93ms dotnet 9.0.301
csharp 2-http3.cs 536ms 12ms 93.9MB 627ms 123ms dotnet 9.0.301
kotlin 1-m.kt 2119ms 180ms 229.3MB 6180ms 533ms kotlin/jvm 21
kotlin 2-m.kt 2206ms 240ms 241.3MB 4083ms 443ms kotlin/jvm 21

json-serde

Input: sample 5000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 315ms 1.5ms 68.7MB 280ms 33ms dotnet 9.0.301
csharp 1.cs 812ms 57ms 143.7MB 833ms 87ms dotnet 9.0.301
kotlin 1-m.kt 848ms 12ms 174.2MB 2307ms 73ms kotlin/jvm 21

Input: canada 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 1553ms 67ms 233.5MB 1740ms 90ms dotnet 9.0.301
kotlin 1-m.kt 1778ms 57ms 662.5MB 4197ms 157ms kotlin/jvm 21
csharp 1.cs 2799ms 121ms 763.8MB 3280ms 460ms dotnet 9.0.301

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 99ms 0.6ms 9.8MB 90ms 0ms dotnet/aot 9.0.301
csharp 2.cs 147ms 1.2ms 22.9MB 133ms 0ms mono 6.12.0
kotlin 2.kt 173ms 14ms 12.4MB 180ms 0ms kotlin/native 2.1.20
kotlin 1-m.kt 193ms 3.9ms 94.9MB 320ms 27ms kotlin/jvm 21
kotlin 2-m.kt 207ms 8.3ms 101.0MB 433ms 37ms kotlin/jvm 21
csharp 2.cs 251ms 1.5ms 29.5MB 233ms 10ms dotnet 9.0.301
kotlin 1.kt 359ms 8.0ms 12.5MB 360ms 0ms kotlin/native 2.1.20
csharp 1.cs 1064ms 15ms 13.0MB 1043ms 3ms dotnet/aot 9.0.301
csharp 1.cs 1315ms 11ms 32.8MB 1303ms 17ms dotnet 9.0.301
csharp 1.cs 3373ms 24ms 45.5MB 3323ms 40ms mono 6.12.0

Input: 1000 3000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 278ms 1.9ms 9.6MB 267ms 0ms dotnet/aot 9.0.301
kotlin 2-m.kt 318ms 3.4ms 212.1MB 533ms 57ms kotlin/jvm 21
kotlin 1.kt 341ms 3.1ms 202.9MB 460ms 37ms kotlin/jvm 21
csharp 2.cs 363ms 4.6ms 22.7MB 347ms 0ms mono 6.12.0
csharp 2.cs 406ms 2.7ms 29.4MB 390ms 10ms dotnet 9.0.301
kotlin 2.kt 475ms 5.0ms 12.4MB 503ms 0ms kotlin/native 2.1.20
kotlin 1.kt 1030ms 1.3ms 12.4MB 1057ms 7ms kotlin/native 2.1.20
csharp 1.cs 3124ms 12ms 13.5MB 3100ms 13ms dotnet/aot 9.0.301
csharp 1.cs 4086ms 597ms 33.3MB 4063ms 23ms dotnet 9.0.301
csharp 1.cs timeout 0.0ms 45.8MB 4940ms 50ms mono 6.12.0

Input: 100 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 56ms 2.8ms 10.1MB 40ms 0ms dotnet/aot 9.0.301
csharp 2.cs 94ms 2.2ms 22.8MB 77ms 3ms mono 6.12.0
kotlin 2.kt 95ms 0.7ms 12.8MB 90ms 0ms kotlin/native 2.1.20
kotlin 1.kt 121ms 0.6ms 12.8MB 117ms 0ms kotlin/native 2.1.20
kotlin 1-m.kt 153ms 1.1ms 90.5MB 293ms 23ms kotlin/jvm 21
kotlin 2-m.kt 170ms 13ms 96.5MB 367ms 33ms kotlin/jvm 21
csharp 2.cs 174ms 3.0ms 29.6MB 150ms 10ms dotnet 9.0.301
csharp 1.cs 1631ms 16ms 32.4MB 1617ms 17ms dotnet 9.0.301
csharp 1.cs 1825ms 7.4ms 28.6MB 1813ms 0ms mono 6.12.0
csharp 1.cs 1831ms 2.3ms 12.9MB 1813ms 0ms dotnet/aot 9.0.301

merkletrees

Input: 17

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 389ms 8.7ms 680.7MB 447ms 90ms kotlin/jvm 21
csharp 2.cs 551ms 10ms 119.2MB 507ms 87ms dotnet/aot 9.0.301
csharp 1.cs 630ms 2.9ms 147.3MB 580ms 127ms dotnet/aot 9.0.301
csharp 2.cs 714ms 12ms 136.7MB 647ms 93ms dotnet 9.0.301
csharp 1.cs 753ms 7.5ms 167.4MB 700ms 133ms dotnet 9.0.301
csharp 1.cs 1373ms 35ms 139.5MB 1567ms 183ms mono 6.12.0
kotlin 1.kt 1857ms 13ms 89.9MB 1940ms 43ms kotlin/native 2.1.20

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 2.cs 139ms 5.9ms 57.8MB 110ms 33ms dotnet/aot 9.0.301
kotlin 1-m.kt 159ms 6.4ms 207.2MB 217ms 37ms kotlin/jvm 21
csharp 1.cs 163ms 8.0ms 72.7MB 123ms 50ms dotnet/aot 9.0.301
kotlin 1.kt 258ms 3.7ms 25.7MB 263ms 10ms kotlin/native 2.1.20
csharp 2.cs 267ms 8.1ms 75.7MB 220ms 40ms dotnet 9.0.301
csharp 1.cs 276ms 1.5ms 89.7MB 243ms 53ms dotnet 9.0.301
csharp 1.cs 277ms 2.7ms 69.5MB 250ms 37ms mono 6.12.0

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1n.kt 351ms 1.9ms 3.5MB 340ms 0ms kotlin/native 2.1.20
csharp 9.cs 365ms 5.3ms 27.6MB 343ms 10ms dotnet 9.0.301
csharp 8.cs 373ms 3.5ms 9.8MB 360ms 0ms dotnet/aot 9.0.301
csharp 8.cs 425ms 6.0ms 27.6MB 410ms 7ms dotnet 9.0.301
kotlin 1.kt 443ms 2.0ms 49.2MB 487ms 17ms kotlin/jvm 21
csharp 8.cs 1248ms 2.0ms 20.3MB 1230ms 0ms mono 6.12.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1n.kt 38ms 0.7ms 3.6MB 30ms 0ms kotlin/native 2.1.20
csharp 8.cs 46ms 1.5ms 9.9MB 30ms 0ms dotnet/aot 9.0.301
csharp 8.cs 97ms 3.2ms 27.5MB 77ms 7ms dotnet 9.0.301
csharp 9.cs 99ms 5.9ms 27.9MB 73ms 10ms dotnet 9.0.301
kotlin 1-m.kt 118ms 1.1ms 49.4MB 167ms 13ms kotlin/jvm 21
csharp 8.cs 168ms 3.1ms 22.4MB 153ms 0ms mono 6.12.0

pidigits

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 1.cs 3272ms 12ms 13.9MB 3167ms 100ms dotnet/aot 9.0.301
csharp 1.cs 3667ms 43ms 38.1MB 3650ms 133ms dotnet 9.0.301
kotlin 1.kt 3717ms 19ms 358.9MB 4580ms 100ms kotlin/jvm 21
kotlin 1n.kt timeout 0.0ms 26.9MB 3970ms 1520ms kotlin/native 2.1.20
kotlin 2n.kt timeout 0.0ms 30.9MB 5110ms 127ms kotlin/native 2.1.20

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 1.cs 767ms 3.0ms 13.5MB 727ms 27ms dotnet/aot 9.0.301
kotlin 1-m.kt 983ms 36ms 353.7MB 1773ms 90ms kotlin/jvm 21
csharp 1.cs 1011ms 7.1ms 37.6MB 1100ms 37ms dotnet 9.0.301
kotlin 1n.kt timeout 0.0ms 27.0MB 4003ms 1517ms kotlin/native 2.1.20
kotlin 2n.kt timeout 0.0ms 30.4MB 5110ms 123ms kotlin/native 2.1.20

regex-redux

Input: 2500000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 6.cs 1757ms 7.6ms 418.7MB 1660ms 147ms dotnet/aot 9.0.301
csharp 5.cs 2065ms 6.3ms 442.7MB 2103ms 180ms dotnet 9.0.301
csharp 6.cs 2760ms 105ms 440.5MB 2710ms 180ms dotnet 9.0.301
csharp 5.cs 4197ms 15ms 419.1MB 4093ms 153ms dotnet/aot 9.0.301
kotlin 1.kt timeout 0.0ms 173.4MB 5410ms 47ms kotlin/jvm 21
kotlin 1n.kt timeout 0.0ms 226.8MB 5063ms 120ms kotlin/native 2.1.20

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 6.cs 191ms 1.6ms 48.1MB 167ms 17ms dotnet/aot 9.0.301
csharp 5.cs 299ms 13ms 72.7MB 267ms 33ms dotnet 9.0.301
csharp 6.cs 392ms 2.4ms 69.9MB 363ms 27ms dotnet 9.0.301
csharp 5.cs 437ms 3.0ms 48.1MB 417ms 13ms dotnet/aot 9.0.301
kotlin 1-m.kt 841ms 4.2ms 134.6MB 1283ms 37ms kotlin/jvm 21
kotlin 1n.kt 3213ms 39ms 51.1MB 3283ms 77ms kotlin/native 2.1.20

secp256k1

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 1.cs 2863ms 11ms 13.3MB 2823ms 30ms dotnet/aot 9.0.301
csharp 1.cs 2987ms 61ms 35.4MB 3060ms 40ms dotnet 9.0.301
kotlin 1.kt 3074ms 30ms 231.8MB 4047ms 73ms kotlin/jvm 21

Input: 500

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
csharp 1.cs 733ms 3.3ms 13.0MB 713ms 7ms dotnet/aot 9.0.301
kotlin 1-m.kt 987ms 13ms 231.9MB 1760ms 47ms kotlin/jvm 21
csharp 1.cs 1008ms 4.1ms 35.4MB 1107ms 17ms dotnet 9.0.301