Swift VS Zig 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
zig 1.zig 1872ms 186ms 49.0MB 1840ms 17ms zig 0.14.1
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
zig 1.zig 152ms 2.9ms 7.0MB 140ms 0ms zig 0.14.1
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
zig 2-m.zig 637ms 8.5ms 1.4MB 2413ms 0ms zig 0.14.1
zig 3-i.zig 1765ms 1.9ms 1.0MB 1757ms 0ms zig 0.14.1
swift 1.swift 2463ms 7.5ms 5.5MB 2453ms 0ms swift 6.1.2
zig 1.zig 2719ms 3.6ms 1.0MB 2710ms 0ms zig 0.14.1

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
zig 2-m.zig 60ms 0.6ms 1.4MB 200ms 0ms zig 0.14.1
zig 3-i.zig 147ms 0.3ms 1.0MB 140ms 0ms zig 0.14.1
swift 1.swift 213ms 2.3ms 5.5MB 200ms 0ms swift 6.1.2
zig 1.zig 229ms 2.1ms 1.0MB 220ms 0ms zig 0.14.1

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
zig 1.zig 88ms 0.8ms 1.0MB 80ms 0ms zig 0.14.1
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
zig 1.zig 11ms 0.8ms 1.0MB 0ms 0ms zig 0.14.1
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
zig 1.zig 0.9ms 0.0ms 1.1MB 0ms 0ms zig 0.14.1
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
zig 1-m.zig 318ms 0.8ms 67.1MB 840ms 23ms zig 0.14.1
zig 1.zig 499ms 2.8ms 28.0MB 477ms 13ms zig 0.14.1
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
zig 1-m.zig 65ms 1.8ms 54.3MB 133ms 33ms zig 0.14.1
zig 1.zig 66ms 2.2ms 15.4MB 50ms 3ms zig 0.14.1
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
zig 3.zig 198ms 1.1ms 1.0MB 190ms 0ms zig 0.14.1
zig 2.zig 280ms 0.5ms 1.0MB 270ms 0ms zig 0.14.1
zig 1.zig 315ms 0.8ms 1.1MB 303ms 0ms zig 0.14.1
swift 7.swift 346ms 2.1ms 9.9MB 337ms 0ms swift 6.1.2

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
zig 3.zig 22ms 0.3ms 1.0MB 10ms 0ms zig 0.14.1
zig 2.zig 30ms 0.1ms 1.0MB 20ms 0ms zig 0.14.1
zig 1.zig 34ms 0.6ms 1.1MB 30ms 0ms zig 0.14.1
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
zig 1.zig 2450ms 12ms 2.2MB 2420ms 17ms zig 0.14.1
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
zig 1.zig 569ms 4.0ms 1.8MB 560ms 0ms zig 0.14.1
swift 1.swift 1865ms 11ms 7.0MB 1853ms 0ms swift 6.1.2