FIELD REPORT // RC-1B-PT+IT // 2608.17981 VIEW SOURCE / REPRODUCE ON GITHUB
Frozen mechanism / unseen books

The loop holds.

On eight previously unseen PG-19 books, identical frozen Gemma 3 1B PT weights, and a protocol committed before evaluation, fixed recirculation cut aggregate perplexity by 13.503%.

01

The validation result

8 unseen books // 40 windows // 40,920 next-token targets

Ordinary forward PPL27.232BASELINE
Recirculation PPL23.555FIXED RC
Books improved8 / 8PAIRED NLL
Windows improved32 / 400 TIES
Lower is better // same weights + same token hashes
Ordinary forward27.23190
Fixed recirculation23.55482
−13.503% perplexity Exploratory: −13.676% // Paper: −14.41%
02

Eight books // eight gains

The aggregate is not being dragged by one lucky record

RecordBookBaseline PPLRC PPLReductionImproved
2Travels in Morocco, Vol. 239.620233.057616.564%4 / 5
3Impressions of Theophrastus Such51.019342.433316.829%4 / 5
4Odd Craft, Part 419.828418.34247.494%4 / 5
5The S. W. F. Club19.380117.74078.459%4 / 5
6Frank Merriwell Down South24.816121.413113.713%4 / 5
7Critical Miscellanies, Vol. 231.053125.076319.247%4 / 5
8From Sand Hill to Pine36.062032.230410.625%4 / 5
9Child's Health Primer14.010111.995714.378%4 / 5

Clean pattern, sharp exception: the first window of every book worsened by 1.46%–3.97%; all 32 later windows improved. The locked protocol kept every unfavorable window. The two largest book gains account for only 34.3% of positive NLL gain.

03

The mechanism

A measured leak from deep state to shallow state, one token later

Token
t
Destination
layer 4
Source
layer 11
Readout
first pass
d′ = (1 − αt) d + αt (‖d‖₂ / ‖s‖₂) s
α = 0.15 // 10-token ramp // one additional iteration // hidden-axis L2 norm match

Mechanical sequence

01 // warmup
No K/V committed on the first rolling step.
02 // capture
Take residual output after destination layer 4.
03 // normalize
Rescale layer-11 source to the destination vector's L2 magnitude.
04 // mix
Convex blend at αtt, then inject as input to layer 5.
05 // advance
Commit only the rolling pair's left token; the newest token remains first-pass readout.

Fixed calibration

Source → target
11 → 4, zero-based
Mix
α = 0.15 // β = 0.85
Ramp
αt = min(t / 10, 1) × 0.15
Recurrence
1 additional iteration
Weights
999,885,952 // frozen // unchanged
04

Matched protocol

Nothing changes between lanes except recirculation state flow

Model lane

Checkpoint
google/gemma-3-1b-pt
Revision
fcf18a2…d8eb29
Artifact hash
ee5250f6…69cb27
Numerics
bfloat16 model // float32 NLL
Backend
PyTorch 2.10 // MPS // eager attention

Data lane

Corpus
PG-19 test, pinned parquet mirror
Selection
First 5 complete windows × unseen records 2–9
Window
1,024 tokens // no padding
Scored
1,023 targets per window
Identity
Ordered per-window SHA-256 verified in both lanes
05

Safety interlocks

The positive number only counts if the machine is doing the intended computation

Ordinary path

Vendored baseline and official Transformers logits are bitwise equal on the real checkpoint.

Frozen steel

No trainable parameters; version counters remain unchanged after evaluation.

Layer routing

530 mixes for 530 fixture tokens, each with destination/source shape [1, 2, 1152].

Norm coupling

Source is rescaled per token on the hidden axis before α/β mixing.

Causal seal

Changing tokens 514–529 produces zero change through position 513, crossing the 512-token sliding-attention boundary.

Cache timing

Native cache lengths match: 511 positions in sliding layers and 529 in full-attention layers.

Sample seal

Records 2–9 and all 40 ordered hashes are locked; no record or token hash overlaps the exploratory sample.

Public adapter

First-64-token logits and a full 1,024-token target-loss vector exactly match the reference-derived evaluator.

06

Shop cost

Quality went up; serial prefill throughput went through the floor

117.2×

The confirmatory reference-style path walks the full prefill token by token: 10.585 seconds for ordinary forward versus 1,240.263 seconds for recirculation. It validates the method, not production latency.

Observed MPS driver allocation

+2.340 GB sampled after synchronized windows
6.137 GB → 8.478 GB

07

The loop hits the road

Locked Gemma 3 1B IT transfer // two signals, two regressions

Capability status: MIXED. The exact PT-calibrated mechanism moved MMLU-Pro and normalized HellaSwag upward, but GSM8K and IFEval downward. Lower PG-19 perplexity did not transfer uniformly into useful-task accuracy.

MMLU-Pro+2.38POINTS // 42
HellaSwag norm+2.00POINTS // 100
GSM8K flexible−10.00POINTS // 50
IFEval strict−4.00POINTS // 50
Locked primary metricBaselineRCDeltaFlips + / −Paired pCall
MMLU-Pro exact match9.524%11.905%+2.381 pp2 / 11.000IMPROVED
GSM8K flexible exact match40.000%30.000%−10.000 pp3 / 80.227REGRESSED
IFEval prompt strict58.000%54.000%−4.000 pp3 / 50.727REGRESSED
HellaSwag normalized41.000%43.000%+2.000 pp6 / 40.754IMPROVED

What changed

MMLU
One gain was stricter answer formatting: baseline knew D but the extractor rejected bold D; recirculation emitted (D).
GSM8K
Three wrong→right flips were outweighed by eight right→wrong flips, including double-counting dozen prices.
IFEval
Extra text sometimes completed structure, but also added forbidden capitals, surplus answers, or a postamble.
HellaSwag
Normalized choice scoring gained two net items; raw accuracy stayed exactly 43% → 43%.

Capability shop cost

Baseline
1,690.40 s evaluator time
Recirculation
6,111.64 s evaluator time
Combined
2 h 10 m 2 s // 3.62× lane ratio
Output length
Longer on 91 / 142 generative pairs; +5,868 tokens net
Verification
All prompt, token, config, score, frozen-weight, cache, and causal checks passed
Capability uncertainty // no clean transfer claim

Every paired-bootstrap interval includes zero and every exact paired p-value is at least 0.227. These fixed subsets are directional evidence, not full-benchmark estimates. The two positive primary movements are small; the 10-point GSM8K regression is the largest capability delta observed. Read the full paired report or inspect the machine-readable comparison.

08

Dust in the bearings

What this result does and does not establish

Locked confirmation // broader, still bounded

The current confirmatory run evaluates 40,920 predicted tokens across 40 windows from eight previously unseen books—about 0.379% of the paper's 10.8M-token PG-19 evaluation. Its 13.503% reduction is close to the paper's 14.41%, but eight sequential records are not a substitute for the full corpus.

Earlier exploratory run // preserved

The earlier exploratory run used 10 windows and 10,230 targets from records 0–1, reducing perplexity by 13.676% with 8 of 10 windows improved. Its initial two-window pilot worsened by 0.396%; it was extended once by a content-blind rule and then stopped. Those artifacts and caveats remain intact and are not presented as the current confirmatory sample.

Systematic window boundary exception

In the locked confirmatory run, window 0 of all eight books worsened by 1.46%–3.97%, while every one of the 32 later windows improved. The protocol retained all eight unfavorable windows. This pattern is real in the sample and unexplained; it is a reason to avoid overgeneralizing the aggregate.

Earlier exploratory mask failure // caught and rejected

During the earlier exploratory work, one diagnostic incorrectly gave sliding layers the full-attention mask, inflating pilot baseline PPL to 75.636. An official-forward equivalence check exposed it. Native 512-token sliding masks restored pilot baseline PPL to 19.201; only corrected numbers appear in either experiment's final result files.

Paper ambiguities and uncertainty

The paper does not pin software, model, tokenizer, data revisions, dtype, or device. It introduces the 1B ten-token ramp but does not explicitly state whether Table 1 includes it. The confirmatory whole-book bootstrap is 10.70%–16.12%, but these are sequential rather than randomly sampled books, so it is descriptive stability evidence—not population-level confidence.

Perplexity did not transfer cleanly

The PT artifact establishes lower perplexity on its specified evaluations—not an equivalent gain in intelligence. The new IT capability milestone is mixed: two small positive primary deltas coexist with GSM8K and IFEval regressions. It still does not establish broad gains in reasoning, coding, instruction following, agentic task completion, or general model intelligence. The paper's near-zero generation-latency claim is also not tested here: this implementation measures serial reference computation.