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Performance

go-ruby-date/date is the pure-Go library that rbgo binds for Ruby's date. This page records a comparative benchmark of that module against the reference Ruby runtimes, part of the ecosystem-wide per-module parity suite.

What is measured

The same Ruby script — Date.parse + strftime + date arithmetic in a loop — is run under every runtime. rbgo's number reflects this pure-Go library doing the work; every other column is that interpreter's own date stdlib. So the comparison is the Ruby-visible operation, apples-to-apples across interpreters. The script prints a deterministic checksum and its output is checked byte-identical to MRI before timing.

  • Host: Apple M4 Max, macOS (darwin/arm64). Method: best-of-5 wall time (best, not mean, to suppress scheduler noise); single-shot processes, no warm-up beyond the script's own loop.
  • Runtimes: ruby 4.0.5 +PRISM (MRI, the oracle) and ruby --yjit; jruby 10.1.0.0 (OpenJDK 25); truffleruby 34.0.1 (GraalVM CE Native).
  • The benchmark script and harness live in rbgo's repo under bench/modules/ (date.rb + run.sh). Reproduce: RBGO=./rbgo TRUFFLE=truffleruby bash bench/modules/run.sh 5.

Result (best of 5, ms)

Runtime time vs MRI
rbgo (go-ruby-date) 230 0.53×
MRI (ruby 4.0.5) 430 1.00×
MRI + YJIT 410 0.95×
JRuby 10.1.0.0 1510 3.51×
TruffleRuby 34.0.1 8400 19.53×

rbgo runs on go-ruby-date and is ~2x faster than MRI here (0.53x). Parse + format + arithmetic is cheaper in the compiled pure-Go library than in MRI's date stdlib.

Honest framing

JRuby and TruffleRuby are timed cold, single-shot, so they carry JVM / Graal startup on every run — read them as one-shot ruby file.rb costs, the same way rbgo and MRI are measured, not as steady-state JIT numbers. Rows that complete in well under ~200 ms carry the most relative noise; treat their ratios as order-of-magnitude. These are real measured numbers from the 2026-06-29 run — nothing is cherry-picked.