
GPT-S-1.4M
GPT-S-1.4M a first-generation model in the GPT-S small-model family built on the T-X3 architecture: 1.4M parameters, 6B training tokens, a custom 4K tokenizer, 5 layers, and all new Exclusive Grouped-query Attention (XGQA), trained from scratch on a 5-source corpus.
See how it compares to similar models here: Open SLM Leaderboard
Benchmarks
All evaluations use zero-shot multiple-choice scoring. Normalized accuracy is reported where available.
| Benchmark | Score |
|---|---|
| HellaSwag | 26.89% |
| ARC-Easy | 31.57% |
| ARC-Challenge | 21.93% |
| ARC Average | 26.75% |
| PIQA | 55.17% |
| ArithMark 2 | 25.16% |
Architecture
| Component | Details |
|---|---|
| Position encoding | RoPE, theta=2,500 |
| Normalization | RMSNorm |
| Feed-forward | SwiGLU |
| Attention | Exclusive Grouped-query attention, 4 query heads / 2 KV heads |
| Embeddings | Weight tied |
| Context length | 384 tokens |
Config
vocab_size = 4,096
hidden_size = 128
num_layers = 5
num_heads = 4
num_kv_heads = 2
head_dim = 32
intermediate = 341
block_size = 384
rope_theta = 2,500
Training
GPT-S-1.4M was trained from scratch for 6B tokens on a mixed English corpus built around educational web text, synthetic textbook-style material, and higher-quality web text.
| Source | Dataset | Mix | Purpose |
|---|---|---|---|
| FineWeb-Edu | HuggingFaceFW/fineweb-edu | 15% | Primary educational web text |
| Cosmopedia v2 | HuggingFaceTB/smollm-corpus | 30% | Synthetic textbook-style coverage |
| FineWeb-HQ | epfml/FineWeb-HQ | 20% | Higher-quality general web text |
| Ultra-FineWeb QA | openbmb/Ultra-FineWeb L3 English QA slice | 20% | Question-answer style web text |
| Ultra-FineWeb Multi-style | openbmb/Ultra-FineWeb L3 English multi-style slice | 15% | Broader writing-style coverage |
Hyperparameters
| Hyperparameter | Value |
|---|---|
| Optimizer | AdamW |
| Adam betas | 0.9 / 0.95 |
| Weight decay | 0.01 |
| Peak learning rate | 3.5e-3 |
| Minimum learning rate | 0 |
| LR schedule | Warmup-stable-decay |
| Warmup steps | 2,000 |
| Decay start | 80% of configured training run |
| Training tokens | 6B |
| Total batch size | 294,912 tokens |
| Microbatch | 256 x 384 tokens |
| Gradient accumulation steps | 3 |
| Gradient clipping | 1.0 |
| Precision | bfloat16 autocast |
Usage
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch
model_name = "AxiomicLabs/GPT-S-1.4M"
tokenizer = AutoTokenizer.from_pretrained(model_name, trust_remote_code=True)
model = AutoModelForCausalLM.from_pretrained(
model_name,
trust_remote_code=True,
torch_dtype=torch.bfloat16,
device_map="auto",
)
prompt = "The future of AI is"
inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
with torch.inference_mode():
output = model.generate(
**inputs,
max_new_tokens=80,
do_sample=True,
temperature=0.8,
top_p=0.95,
repetition_penalty=1.1,
no_repeat_ngram_size=4,
)
print(tokenizer.decode(output[0], skip_special_tokens=True))
Limitations
This is a very small base language model. It is not instruction tuned, has limited factual capacity, and uses a 384-token context window.