en1_full_d125m_ctx1024

d125m (134.1M parameters) on FineWeb sample (4 files), trained on RTX 3060 12GB (Home GPU). Started 23 Sep 2026, ended 24 Sep 2026.

Hypothesis

The winning recipe at EN0's full budget (1.33B tokens) beats EN0, and a plain AdamW GPT-2 124M trained on the same number of tokens.

What we learned

Yes: FineWeb 1.1062, 4.0% better than EN0, every set 3 to 4% better. During training 1.1322 vs GPT-2 124M's 1.1755 at the same tokens (-3.7%); GPT-2 needs twice the tokens to match.

Scores

Lower is better on the headline; change against the parent run, EN0.

FineWeb validation
1.10625
bits per byte · headline
−3.9%
Validation, in training
1.1322
bits per byte
−3.9%
Every published score of EN1-full, against its parent EN0
Test setEN1-fullEN0 (parent)Change
FineWeb validation headline
About 15,000 FineWeb web documents never used in training, scored with a 1,024-token window.
1.10625 1.15174−3.9%
FineWeb validation, clean
The same documents minus any that overlap the training text.
1.12346 1.16785−3.8%
Pooled, five sets
All five English test sets pooled.
1.13758 1.18255−3.8%
WikiText-103 test
Good and featured Wikipedia articles, a standard language-modelling benchmark.
1.16525 1.21418−4.0%
enwik8 test
Raw Wikipedia markup; a character-level compression benchmark.
1.38144 1.42598−3.1%
text8 test
Lower-cased Wikipedia text with markup stripped; a character-level benchmark.
1.25837 1.30127−3.3%
FineWeb validation, during training
The validation number measured during training, the way the GPT-2 124M reference was measured, so the two can be compared.
1.1322 1.1781−3.9%

Bits per byte: how many bits the model needs, on average, to predict each byte of text it never saw in training. Lower is better, and it compares models with different tokenizers fairly, because every model is charged for the same bytes.

Curves

Training loss

Cross-entropy per token, by step. The first few percent of the run, far higher, run off the top; hover or the table has every value.

Held-out bits per byte

The validation split, evaluated during training, by step. Lower is better.

Throughput

Tokens per second, by step.

Model

Preset
d125m
Parameters
134,105,856
Outside embeddings
84,953,856
Layers · heads · width
12 · 12 · 768
Tokenizer
Shared unigram 32k

Muon + AdamW, rope, qk_norm, relu^2, untied head, context 1024

Data

Slice
FineWeb sample (4 files)
Words
—
Training tokens
3,253,318,552
Passes
0.41 passes
Tokens seen
1,332,314,112

Compute

GPU
RTX 3060 12GB
Where
Home GPU
Steps
27,106 / 27,106
GPU hours
14.85
Cost
—
Spot restarts
—

Lineage

homed125m