CUDA broad-fifth research workflow

Historical: describes the code as of 2026-10-22; its fits refined with the finite-difference Newton, since replaced by exact derivatives, so its fit timings are not current. See the current fit methods.

This private-model experiment reduced full 512-square workflow time by 54–65% while preserving the complete tested phase arrays and search records. It does not change the public higher-order estimator or its defaults.

Workload and boundary

Each paired fresh process used the same full detector data, native fitting, 200 primary trials, 400 broad-fifth TPE trials, and a 3,000-evaluation Newton cap. Output used Auto sampling. All measurements below used the same physical Blackwell Max-Q GPU, with six repetitions per variant and scan size.

Acquisition	Valid BF pixels	Auto	Before p50	Candidate p50 / p95 / max
A	8,807	3x	27.847 s	12.404 / 13.853 / 13.984 s
B	101	1x	8.788 s	3.115 / 3.345 / 3.402 s
C	8,930	4x	40.859 s	18.660 / 18.968 / 19.023 s
D	9,298	3x	29.187 s	13.103 / 14.224 / 14.536 s

Workflow time includes loading, preparation, both fitting stages, reconstruction, host transfer and buffered output. It excludes imports, evidence bookkeeping and process cleanup. Candidate process-wall medians were 17.171, 7.658, 23.140 and 17.661 seconds respectively. Raw per-stage timings, process boundaries and memory observations are retained in experiment group 1022-freshfinal. Filesystem caches and background host activity were uncontrolled; six samples give preliminary p95 estimates.

Changes and parity

The research evaluator reuses detector-side optical calculations, shares coefficients within each block, and groups eight independent candidates per saturated-grid launch. The sampler batches independent inverse-CDF work, reuses the existing compiled central log-CDF, and ranks KDE candidates on CUDA with an original-calculation fallback near ties. Scientific objective evaluation remains on CUDA. Candidate generation and the float64 Newton controller remain hybrid CPU/GPU work.

All 48 paired workflows across four acquisitions at 256 and 512 scan sizes matched complete phase arrays, proposals, coarse scores, Newton trajectories, stopping states and calibration. Twelve additional full-field searches at three other seeds also matched frozen references. KDE density values are not claimed bitwise identical to the CPU library; selected proposals and complete scientific outputs were identical on the tested paths.

The combined prototype also passed an actual headed Jupyter/ShowPtycho check on acquisitions A and C, including Auto phase/FFT display and a pointer-driven C10 adjustment. This is functional acceptance, not an FPS benchmark. Evidence groups: 1022-consumer-broad-final and 1022-seedfinal.

Limits and integration status

The frozen research source started from db305309; the public four-case reuse branch was at 6bb36fa0 during qualification. Prototype dependencies and runners were snapshotted before execution in the private archive.

The historical research objective has a different numerical contract from the public optional higher-order estimator. These improvements must not silently replace that estimator. Public integration needs a separate numerical review and regression qualification. The empirical reference is not physical ground truth, and unchanged results do not establish a global minimum.

Rejected changes include full geometry caching, pointwise score fusion, two-candidate grouping and smaller compiled trial arrays when they changed objective rounding. Single-candidate specialization gave inconsistent workflow gains. The shared-FFT mixed-compiler-cache discrepancy remains held. No theoretical performance minimum, deployment or release is claimed.