Swift VS D 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
d 1.d 2199ms 4.7ms 312.4MB 2163ms 43ms ldc2 1.41.0
swift 1.swift 2692ms 22ms 53.8MB 2657ms 20ms swift 6.1.2
d 1.d 3022ms 5.5ms 314.5MB 3190ms 57ms dmd 2.111.0

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1.d 205ms 3.7ms 207.6MB 177ms 17ms ldc2 1.41.0
swift 1.swift 240ms 0.7ms 11.9MB 230ms 0ms swift 6.1.2
d 1.d 262ms 2.2ms 211.2MB 230ms 17ms dmd 2.111.0

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1-im.d 377ms 1.9ms 3.0MB 1423ms 0ms ldc2 1.41.0
d 2-im.d 1130ms 21ms 3.0MB 4303ms 3ms ldc2 1.41.0
d 1-i.d 1488ms 1.6ms 2.9MB 1480ms 0ms ldc2 1.41.0
swift 1.swift 2463ms 7.5ms 5.5MB 2453ms 0ms swift 6.1.2
d 1.d 3115ms 16ms 2.9MB 3107ms 0ms ldc2 1.41.0
d 2-i.d 3226ms 2.2ms 2.9MB 3217ms 0ms ldc2 1.41.0
d 1.d 3535ms 4.3ms 4.6MB 3527ms 0ms dmd 2.111.0
d 1-im.d 4491ms 66ms 4.8MB 17510ms 0ms dmd 2.111.0
d 1-i.d timeout 0.0ms 4.6MB 4990ms 0ms dmd 2.111.0
d 2-i.d timeout 0.0ms 4.5MB 4990ms 0ms dmd 2.111.0
d 2-im.d timeout 0.0ms 4.9MB 19723ms 0ms dmd 2.111.0

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1-im.d 37ms 1.0ms 3.0MB 110ms 0ms ldc2 1.41.0
d 2-im.d 96ms 1.9ms 3.0MB 350ms 0ms ldc2 1.41.0
d 1-i.d 123ms 0.1ms 2.9MB 120ms 0ms ldc2 1.41.0
swift 1.swift 213ms 2.3ms 5.5MB 200ms 0ms swift 6.1.2
d 1.d 264ms 3.2ms 2.9MB 253ms 0ms ldc2 1.41.0
d 2-i.d 266ms 0.6ms 2.8MB 260ms 0ms ldc2 1.41.0
d 1.d 297ms 3.2ms 4.6MB 290ms 0ms dmd 2.111.0
d 1-im.d 377ms 1.2ms 4.9MB 1430ms 0ms dmd 2.111.0
d 2-im.d 527ms 0.8ms 4.9MB 2003ms 0ms dmd 2.111.0
d 1-i.d 882ms 15ms 4.6MB 873ms 0ms dmd 2.111.0
d 2-i.d 1390ms 1.3ms 4.6MB 1380ms 0ms dmd 2.111.0

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1.d 111ms 2.1ms 2.9MB 100ms 0ms ldc2 1.41.0
swift 3-m.swift 139ms 1.6ms 20.7MB 400ms 3ms swift 6.1.2
d 1.d 640ms 2.7ms 4.6MB 630ms 0ms dmd 2.111.0

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1.d 14ms 0.5ms 2.9MB 10ms 0ms ldc2 1.41.0
swift 3.swift 37ms 0.3ms 14.2MB 30ms 0ms swift 6.1.2
d 1.d 68ms 0.4ms 4.8MB 60ms 0ms dmd 2.111.0

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1.d 1.6ms 0.1ms 3.0MB 0ms 0ms ldc2 1.41.0
d 1.d 2.1ms 0.2ms 5.1MB 0ms 0ms dmd 2.111.0
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
d 1-m.d 643ms 26ms 48.5MB 2040ms 13ms ldc2 1.41.0
swift 2-m.swift 1361ms 16ms 74.3MB 4960ms 37ms swift 6.1.2
d 1-m.d 1937ms 33ms 50.0MB 5567ms 10ms dmd 2.111.0

Input: 250000_in

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1-m.d 95ms 8.6ms 39.5MB 253ms 23ms ldc2 1.41.0
d 1-m.d 211ms 7.1ms 39.9MB 597ms 10ms dmd 2.111.0
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
d 1.d 360ms 0.2ms 2.9MB 350ms 0ms ldc2 1.41.0
d 2.d 361ms 1.9ms 2.9MB 350ms 0ms ldc2 1.41.0
d 1.d 678ms 2.2ms 4.6MB 670ms 0ms dmd 2.111.0
d 2.d 2033ms 7.7ms 4.8MB 2023ms 0ms dmd 2.111.0

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 2.d 38ms 0.3ms 2.9MB 30ms 0ms ldc2 1.41.0
d 1.d 39ms 0.4ms 2.9MB 30ms 0ms ldc2 1.41.0
swift 7.swift 39ms 0.9ms 9.9MB 30ms 0ms swift 6.1.2
d 1.d 72ms 0.1ms 4.8MB 60ms 0ms dmd 2.111.0
d 2.d 207ms 2.8ms 4.8MB 197ms 0ms dmd 2.111.0

pidigits

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
d 1.d 2431ms 4.5ms 8.1MB 2407ms 407ms ldc2 1.41.0
d 1.d 4429ms 9.8ms 10.5MB 4377ms 480ms dmd 2.111.0
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
d 1.d 584ms 4.3ms 8.1MB 563ms 103ms ldc2 1.41.0
d 1.d 1055ms 3.8ms 10.3MB 1050ms 97ms dmd 2.111.0
swift 1.swift 1865ms 11ms 7.0MB 1853ms 0ms swift 6.1.2