later annotation · v1.4Δτ, the exponent contrast quoted on this page, is invariant to affine rescalings of the error but not to monotone non-affine ones — under log(1+err) and √err its sign reverses. It is retained here as the pre-registered test it was, and the paper now leads with a model-free floor-referenced contrast instead. See coordinate-audit.html.
Project ASPECT-D · Results · outcome class S1 · generated 2026-08-06 14:24 UTC

Refinement steps buy intelligibility, not identity — measured

Per-metric (width, depth, steps) scaling for masked-diffusion TTS. Every number on this page comes from results/artifacts/runs.csv, results/artifacts/fits.json or results/artifacts/c_layer.json. Declared outcome class: S1 — test-time scaling is metric-selective — refinement steps buy intelligibility far faster than speaker identity.

Headline Δτ = τWER − τSIM = 0.110, 95% run-level bootstrap CI [0.092, 0.131] → H-D2 supported. κWER = 3.000, CI [3.000, 3.000] → H-D3 not supported. Δρ = ρSIM − ρWER = 0.174, CI [-0.711, 0.388] → H-D1 not supported. Power gate G4: passed. Surface: 225 rows = 15 configs × 3 seeds × 5 T values, 400 eval items each.

§1What was run

ItemValue
Training data2000 h Emilia-EN, 792,064 clips, 64,680 speakers (≥4,000 required), 200 held-out speakers
sec_per_char (Phase 0, median over 10,000 clips) 0.06020
Recipecoarse-to-fine (grid.json backbone.training_objective)
T semanticssteps per level, NFE = 8T (grid.json sampler_frozen.T_definition)
μP base LR (chosen at G1)0.004
Completed runs45
Compute used142.9 / 500 B200-h
SIM-o modelwavlm_large_sv_unispeech(seed-tts-eval)
Eval-harness sanity (G0c, ground-truth audio) WER 3.4% · same-speaker SIM 0.701 · cross-speaker SIM 0.034

§2The step axis (Part B — primary)

Msep: errm(w,d,T) = E + A·w−α + B·d−β + C·T−τ  ·  Msub: errm = E + A·w−α + B·(d·Tκ)−β
Metricα (width)β (depth) τ (steps)τ 95% CIκ κ 95% CIΔAICc(sub−sep)ΔAICc(full−N)
WER1.574 2.0400.836 [0.825, 0.851] 3.000 [3.000, 3.000] 69.3 -15.5
SIM-o0.919 0.5530.726 [0.709, 0.744] 3.000 [3.000, 3.000] 71.3 -5.5

Δτ = 0.110, 95% CI [0.092, 0.131] — excludes 0. Bootstrap: run-level, 2000/2000 replicates converged, RNG 7331. Saturation steps, normalised to each metric's own total T-gain (affine-invariant): T* = 16 for both WER and SIM-o. The raw-scale variant of this statistic (WER 16, SIM-o 8) is withdrawn — the 5% band is 0.67% of WER's range but 11.96% of SIM's, a 17.9× difference in strictness, so the apparent gap was an artifact of scale and not of the models' behaviour.

step_curves
step_curves.svg — Error vs T per metric, every config, normalised to its T=1 value; thick lines are grid means. The per-metric dotted T* markers still drawn in this SVG are computed on each metric's own raw scale and are not comparable across metrics; the figure is being regenerated without them. On the affine-invariant statistic T* = 16 for both metrics.
substitution_plane
substitution_plane.svg — Iso-WER contours in (log T, log d) from M_sub with the fitted slope −κ, and the iso-latency line 8·T·d = const from the measured c_layer.
aniso_contours_T16
aniso_contours_T16.svg — Fitted anisotropy surface at T=16 with the measured config means overlaid; ρ = α/β per metric.
extrapolation
extrapolation.svg — H-D4: the two smaller budgets predict the largest budget under M_full and under the N-only model.

§3Anisotropy at T=16 (Part A — secondary)

Metricαβ ρ=α/βEΔAICc(full−N) shape matters (ΔAICc ≤ −4)
WER1.338 1.9350.692 0.109 -15.5 yes
SIM-o0.893 1.0310.866 0.565 -5.5 yes

Δρ = ρSIM − ρWER = 0.174, CI [-0.711, 0.388]. H-D4 (extrapolation to the largest budget): WER MAPE 20.2% under M_full vs 20.4% under the N-only model; SIM-o 2.4% vs 2.2%.

§4Budget-constrained minima on the measured T ≤ 16 grid

Serial latency per utterance = 8·T·d·c_layer(w) (grid.json latency_model) with c_layer measured on NVIDIA B200 at batch 1: w=256: 0.497 ms, w=320: 0.510 ms, w=384: 0.514 ms, w=448: 0.500 ms, w=512: 0.493 ms, w=640: 0.506 ms, w=768: 0.498 ms, w=832: 0.499 ms, w=960: 0.493 ms, w=1152: 0.502 ms. For each budget the table gives the (w, d, T) point of the measured grid that minimises the fitted Msep prediction subject to the budget. Caveat: T is censored at the grid maximum of 16, and every optimum at ≥ 1000 ms sits exactly on that boundary, so this table supports no depth-versus-steps ordering — on the extended T ≤ 64 grid the ordering reverses. No allocation rule is claimed here.

MetricBudget (ms)Best config wdT latency (ms)predicted err
WER200 B18326 8192 0.3169
WER500 C296012 8379 0.2267
WER1000 C296012 16757 0.1398
WER2000 B538430 161974 0.1159
WER4000 C551236 162272 0.1142
SIM200 B18326 8192 0.6518
SIM500 C296012 8379 0.6299
SIM1000 C296012 16757 0.6133
SIM2000 C464026 161684 0.6071
SIM4000 C464026 161684 0.6071

§5Measured surface

configwdN TWERSIM-o DegenRateUTMOSval loss latency (ms)
A16404 19.7M1 112.8%0.198 39.3%1.52 4.637716
A16404 19.7M2 102.0%0.249 15.5%1.86 4.637732
A16404 19.7M4 77.6%0.289 3.8%2.32 4.637765
A16404 19.7M8 61.3%0.315 1.6%2.64 4.6377130
A16404 19.7M16 53.9%0.327 0.7%2.84 4.6377259
A24488 19.3M1 117.2%0.202 41.8%1.52 4.581832
A24488 19.3M2 86.5%0.267 11.0%1.90 4.581864
A24488 19.3M4 50.8%0.311 1.2%2.40 4.5818128
A24488 19.3M8 34.7%0.338 0.3%2.72 4.5818256
A24488 19.3M16 28.4%0.348 0.1%2.91 4.5818512
A338412 21.2M1 113.9%0.202 40.8%1.52 4.566149
A338412 21.2M2 83.2%0.265 9.8%1.91 4.566199
A338412 21.2M4 34.6%0.319 1.1%2.45 4.5661197
A338412 21.2M8 19.7%0.346 0.0%2.77 4.5661395
A338412 21.2M16 15.9%0.360 0.2%2.96 4.5661789
A432018 22.1M1 115.4%0.203 39.9%1.52 4.574074
A432018 22.1M2 77.1%0.266 7.8%1.93 4.5740147
A432018 22.1M4 30.5%0.320 0.4%2.48 4.5740294
A432018 22.1M8 17.8%0.347 0.0%2.79 4.5740588
A432018 22.1M16 13.6%0.359 0.0%2.94 4.57401176
A525624 18.9M1 115.8%0.194 38.2%1.52 4.611295
A525624 18.9M2 76.2%0.260 9.5%1.91 4.6112191
A525624 18.9M4 34.2%0.313 0.8%2.43 4.6112382
A525624 18.9M8 20.8%0.339 0.2%2.76 4.6112763
A525624 18.9M16 15.3%0.351 0.2%2.92 4.61121527
B18326 49.9M1 112.1%0.212 39.4%1.54 4.550624
B18326 49.9M2 85.1%0.269 9.4%1.93 4.550648
B18326 49.9M4 49.8%0.320 1.7%2.43 4.550696
B18326 49.9M8 33.7%0.345 0.4%2.75 4.5506192
B18326 49.9M16 27.8%0.361 0.1%2.93 4.5506383
B264010 49.2M1 113.9%0.208 43.2%1.51 4.504940
B264010 49.2M2 76.6%0.282 9.0%1.94 4.504981
B264010 49.2M4 33.6%0.341 0.2%2.48 4.5049162
B264010 49.2M8 20.9%0.371 0.2%2.81 4.5049324
B264010 49.2M16 16.0%0.381 0.0%2.98 4.5049648
B351216 50.3M1 114.9%0.212 40.3%1.52 4.497163
B351216 50.3M2 72.9%0.293 7.5%1.96 4.4971126
B351216 50.3M4 26.8%0.347 0.3%2.53 4.4971252
B351216 50.3M8 16.6%0.376 0.0%2.83 4.4971505
B351216 50.3M16 11.9%0.388 0.1%3.00 4.49711010
B444822 53.0M1 108.5%0.212 42.4%1.53 4.510588
B444822 53.0M2 71.6%0.287 7.3%1.97 4.5105176
B444822 53.0M4 28.6%0.347 0.2%2.53 4.5105352
B444822 53.0M8 16.1%0.375 0.1%2.84 4.5105704
B444822 53.0M16 12.0%0.382 0.1%2.99 4.51051408
B538430 53.1M1 112.8%0.209 40.9%1.52 4.5198123
B538430 53.1M2 69.1%0.285 7.2%1.96 4.5198247
B538430 53.1M4 27.4%0.345 0.1%2.52 4.5198493
B538430 53.1M8 16.0%0.372 0.2%2.82 4.5198987
B538430 53.1M16 11.5%0.375 0.1%2.98 4.51981974
C111528 127.4M1 112.8%0.216 38.9%1.54 4.503932
C111528 127.4M2 79.1%0.289 8.8%1.97 4.503964
C111528 127.4M4 35.1%0.338 0.4%2.50 4.5039128
C111528 127.4M8 22.5%0.367 0.1%2.81 4.5039257
C111528 127.4M16 17.1%0.373 0.2%2.98 4.5039514
C296012 132.7M1 115.4%0.216 38.5%1.53 4.503547
C296012 132.7M2 77.9%0.286 6.3%1.96 4.503595
C296012 132.7M4 36.7%0.341 0.7%2.49 4.5035189
C296012 132.7M8 23.2%0.366 0.2%2.81 4.5035379
C296012 132.7M16 18.9%0.373 0.2%2.97 4.5035757
C376818 127.4M1 114.3%0.221 39.5%1.53 4.487972
C376818 127.4M2 76.3%0.296 8.3%1.96 4.4879143
C376818 127.4M4 31.6%0.353 0.7%2.51 4.4879287
C376818 127.4M8 18.4%0.381 0.1%2.83 4.4879573
C376818 127.4M16 14.3%0.392 0.0%2.98 4.48791147
C464026 127.8M1 115.3%0.215 41.7%1.52 4.4889105
C464026 127.8M2 73.1%0.290 7.2%1.97 4.4889211
C464026 127.8M4 28.8%0.352 0.2%2.52 4.4889421
C464026 127.8M8 17.4%0.381 0.0%2.84 4.4889842
C464026 127.8M16 13.4%0.390 0.1%3.01 4.48891684
C551236 113.3M1 112.1%0.219 40.8%1.52 4.4867142
C551236 113.3M2 67.6%0.293 6.5%1.97 4.4867284
C551236 113.3M4 25.0%0.354 0.3%2.54 4.4867568
C551236 113.3M8 13.9%0.379 0.1%2.86 4.48671136
C551236 113.3M16 9.9%0.388 0.0%3.02 4.48672272

§6Gate, cut and calendar history

Gate G6 — pass {"passes": true, "today": "2026-08-06", "next_milestone": "M1_env_mup_done", "due": "2026-08-12", "hard_wall": "2026-08-29", "days_to_wall": 23}
Gate G5 — pass {"passes": true, "used_gpu_hours": 171.8436410319141, "occupancy_gpu_hours": 64.9795189098517, "mean_hours_per_run": 3.6117848808117854, "runs_remaining": -15, "projected_total": 194.3436410319141}
Gate G1 — pass {"argmin_w256": 0.004, "argmin_w640": 0.002, "passes": true, "when": "2026-08-05 23:47 UTC"}
Gate G1b — pass {"argmin_d4": 0.002, "argmin_d24": 0.002, "passes": true, "when": "2026-08-05 23:47 UTC"}
Gate G2 — pass {"passes": true, "checks": {"WER(C3,T=16) <= 0.30": {"pass": true, "value": 0.11250733636706733}, "WER(A3,T=16) <= 0.65": {"pass": true, "value": 0.1612674587067795}, "SIM-o(C3,T=16) >= 0.30": {"pass": true, "value": 0.4081370605202392}, "SIM-o(C3,T=16) >= cross baseline + 0.15": {"pass": true, "value": 0.4081370605202392}, "DegenRate(C3,T=16) <= 0.40": {"pass": true, "value": 0.0}}, "cross_speaker_baseline": 0.03381083719432354, "T_FLAT": false, "wer_C3_T1": 1.1411705989383842, "wer_C3_T16": 0.11250733636706733}
Gate G3 — pass {"passes": true, "configs_with_all_seeds": 15, "threshold": 12, "per_config_seeds": {"A1": [0, 1], "A2": [0, 1], "A3": [0, 1], "A4": [0, 1], "A5": [0, 1], "B1": [0, 1], "B2": [0, 1], "B3": [0, 1], "B4": [0, 1], "B5": [0, 1], "C1": [0, 1], "C2": [0, 1], "C3": [0, 1], "C4": [0, 1], "C5": [0, 1]}, "restarts": {}, "when": "2026-08-06 09:53 UTC"}
Gate G_sampler_integrity — pass {"passes": true, "n_runs": 45, "n_failing": 0, "differing_cell_fraction_range": [0.9819560669456067, 0.9888859832635983], "when": "2026-08-06 14:18 UTC"}
Gate G4 — pass {"passes": true, "n_budgets_passing": {"wer": 3, "sim": 3}, "when": "2026-08-06 14:21 UTC"}

Cuts applied: none — no compute or calendar cut was triggered. Flags: none.

Protocol: protocol.html · theory: motivation.html · implementation: implementation.html · decision: DECISION.md · trail: LOG.md.