Each GC runs the same fixed-parameter conjunction pipeline 10 times to measure throughput variance.
- tolerance-km: Fixed at 72 km
- step-second-ratio: Fixed at 8
- interpolation-stride: Fixed at 50
- cell-ratio: Fixed at 1.30
- lookahead-hours: Fixed at 24
- threshold-km: Fixed at 5.0 km
- iterations: 10 per GC
- heap: 12 GB (-Xmx12g -Xms12g -XX:+AlwaysPreTouch)
| GC | Mean Time | Std Dev | Min | Max | Conjunctions |
|---|---|---|---|---|---|
| G1 | 22.46s | 0.47s | 22.00s | 23.21s | 43770 |
| Parallel | 22.70s | 0.30s | 22.17s | 23.08s | 43770 |
| Shenandoah | 22.73s | 0.22s | 22.44s | 23.11s | 43770 |
| Z | 24.57s | 0.37s | 23.97s | 25.24s | 43770 |
All GCs detect identical conjunctions (43,770). The difference is pure runtime.
G1, Parallel, and Shenandoah are effectively tied (~1% spread). ZGC is ~9% slower.
Recommendation: G1.
