Per-batch GPU timeline (submit, timestamps, query, consume). Startup Draws submit
several ready batches per pump (80 ms startup budget, 16 ms per batch); the output
pool is reserved before the warm-up-pending deferral.
My runs outside the sandbox (Step22.exe, marker removed first, interleaved):
CPU 1.295 / 1.314 / 1.284 / 1.342 s
GPU cached (marker match, -Timeline): 1.197 / 1.121 / 1.133 s
(1,124 / 1,380 / 1,415 GPU tiles; output pool at 655-680 ms in all three)
GPU marker miss: 1.446 (-Timeline), 1.447, 1.312 s (no -Timeline). The 1.447 run's
shape compile ended at 776 ms vs 634-643 ms in its neighbours, so this is
startup variance, not a clear regression; to be watched.
Known tradeoff: startup pumps can stall the main thread 65-108 ms (submit calls run
past the budget); fine before the first view, to check in an interactive viewer.
Audits: hashes w1/w8, walk 5,642/5,642, near 960 / far 1,114 0 diffs vs CPU and
WARP, thin 353, survival ~6.2 GiB, ten captures as step 18.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ