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Linked approachRust bitboard engine
Dates
Recorded
Record idRS-20260825T052959Z-1b3ed9a5

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Technical recordMetrics, gate checks and limitationsRS-20260825T052959Z-1b3ed9a5
valid runoutcome: passsupported-as-testedtier: mechanics-onlyRS-20260825T052959Z-1b3ed9a5

A deterministic central-frontier scheduler replaced at-most-seven root-column jobs with a bounded shared registry of continuation subtrees while retaining ordered floating-point reduction and the old root scheduler as a fallback. On one retained 12-logical-CPU arm64 profile, exact root/frontier comparisons had zero value, action, or task mismatches. The preregistered D5/S7 bounded split reduced the three-repeat median for three roots from 22.034955 s to 19.410905 s (1.1352x) with 0.8823 median worker busy fraction; D4/S7 over eight roots improved from 4.076978 s to 3.232507 s (1.2612x) with 0.9951 busy fraction. A deliberately over-expanded D5 prefix reached 0.9963 busy fraction but created about 41% more logical work and achieved only 1.0102x, which falsified that split and motivated the adaptive coarse split for expensive continuations. This supports the refactor strategy locally but is not a 192-core saturation or policy-strength result.

What it had to pass
  • Sequential/C++-equivalent, root-column, and central-frontier values and actions are exact across at least eight realistic D4/S7 roots at one and maximum local workers, with every task completed exactly once. — observed: Eight strict-FP C++/Rust roots had 0 mismatches. Root/frontier comparisons covered 24 paired decisions at one worker and 24 at 12 workers with 0 value/action/task mismatches; registered and completed task counts matched in every row.
  • Three repeats are value/action deterministic at each tested worker count. — observed: Three repeats at one and 12 workers produced 0 semantic mismatches; worker count changed timing and task placement only.
  • At maximum local workers on at least three D5/S7 roots, median wall time improves at least 10% and worker busy fraction is at least 0.75. — observed: Three roots x three repeats: 22.034955 s root median versus 19.410905 s bounded-frontier median, 1.1352x speedup and 0.8823 median busy fraction.
  • The scheduler safely expresses 192 workers, bounds the frontier and memory, and rejects unsafe memory before allocation. — observed: The allocation-free D7/S7 192-worker plan selected split 1, bounded the worst frontier at 2,401 tasks and projected 2,418,377,728 bytes under an 8 GiB cap. A 16,777,216-entry cache per worker was rejected at 154,618,822,656 bytes; the Rust unit test covers the same fail-closed path.
  • Release Rust tests, native parity, determinism/reflection, npm test, and repository test integration pass or any pre-existing artifact failure is disclosed. — observed: Cargo release tests passed 22/22 after the analytics reflection test was added; npm test passed 137 with 1 unrelated native-binary skip and exercised the Rust decision binary. `make test` stopped at `research-validate`: after this run record was completed, 72 pre-existing gitignored historical artifacts remain absent in this checkout, so the aggregate target cannot reach later steps. The default arm64 C++ build also differed by 1-3 ULP on 7/20 roots because of contraction; the retained -ffp-contract=off comparison passed 8/8 with no action changes in the default build.
Technical recordRecorded metricsRS-20260825T052959Z-1b3ed9a5
d4s7Threads12
rootsPerRepeat
8
repeats
3
rootMedianSeconds
4.0770
frontierMedianSeconds
3.2325
speedup
1.2612
frontierBusyMedian
0.9951
pairedDecisions
24
mismatches
0
d5s7Threads12BoundedSplit
rootsPerRepeat
3
repeats
3
rootMedianSeconds
22.0350
frontierMedianSeconds
19.4109
speedup
1.1352
frontierBusyMedian
0.8823
pairedDecisions
9
mismatches
0
d5s7Threads12OverExpandedSplit
rootMedianSeconds
24.9596
frontierMedianSeconds
24.7075
speedup
1.0102
frontierBusyMedian
0.9963
rootLogicalWork
381,642,037
frontierLogicalWorkMedian
539,523,663
d4s7Threads1
rootsPerRepeat
8
repeats
3
rootMedianSeconds
13.7221
frontierMedianSeconds
13.5473
pairedDecisions
24
mismatches
0
Limitations
  • Mechanics-only CHECK result on one shared 12-logical-CPU arm64 workstation; no x86 or 192-core timing was performed.
  • The timing corpus is eight reusable diagnostic roots at D4 and three at D5, not complete games or a strength cohort.
  • Private worker tables make logical work schedule-dependent. Fine granularity is not monotonically better: the over-expanded D5 arm increased logical work about 41% and failed the speed gate.
  • Worker busy fraction measures timed search-task occupancy and excludes coordinator planning, initialization, and reduction; end-to-end wall time is the primary speed metric.
  • Peak RSS and CPU seconds were not retained. Memory values are exact table-layout projections plus a conservative planner allowance.
  • The default arm64 C++ compiler contracted floating operations; bit-exact native parity on this host required -ffp-contract=off. Actions did not change in the default 20-root diagnostic.

Recorded against Central frontier scheduler parity and within-decision scaling check.

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Record file: research/results/RS-20260825T052959Z-1b3ed9a5.json, validated against research/schemas/result-v1.schema.json.

Run ids
  • RUN-20260825T045058Z-b79f76a2
Contribution ids
  • CT-20260825T052922Z-9a61f2f0
Per-game artifact
runs/RUN-20260825T045058Z-b79f76a2/central-frontier/summary.json (sha256 c9e51481dd12c82dbc6ab550939670e112f65df9aabf3670269edaaa769db3b4, – records)
Machine profiles
  • runs/RUN-20260825T045058Z-b79f76a2/central-frontier/MACH-20260825T045112Z-2d4c14b8.json