Qwen2.5-1.5B-OpenR1-SFT
Built with Qwen. This is the final supervised fine-tuning checkpoint from a token-level study of the transition from SFT to GRPO. It was trained from Qwen/Qwen2.5-1.5B at revision 8faed761d45a263340a0528343f099c05c9a4323. The model weights were modified through supervised fine-tuning; tokenizer and generation settings are the exact saved experiment artifacts.
Training
The SFT stage completed 278 optimizer updates and 20,016 examples, corresponding to one epoch over the selected subset of open-r1/OpenR1-Math-220k at revision e4e141ec9dea9f8326f4d347be56105859b2bd68.
The shared data selection uses complete, locally verified mathematical reasoning traces that fit every model's 4,096-token budget. Overlength examples were excluded rather than truncated. Prompt tokens are masked from the supervised loss. The repository includes the exact selected example IDs and probe IDs in data-selection.json.
| Setting | Value |
|---|---|
| Framework | Prime RL 0.9.0 |
| Prime RL revision | ab5de8fff44b2c4a5c85e24b6e6e3f7d57eee7b1 |
| Seed | 42 |
| Sequence length | 4096 tokens |
| Effective batch | 72 examples |
| Learning rate | 2e-05 |
| Scheduler | cosine |
| Warmup ratio | 0.03 |
| Weight decay | 0.01 |
| Gradient clipping | 1.0 |
| Training precision | bf16 |
| Saved tensor dtypes | F32 |
The independent cross-entropy calculation passed and the final fixed-probe evaluation completed. train_metrics.jsonl contains the training update metrics; evaluation-summary.jsonl contains the fixed train and held-out probe summaries, including teacher-forced and free-generation measurements. These are experiment probe results, not a claim of standard benchmark performance.
Use
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer
repo_id = "zbeeb/Qwen2.5-1.5B-OpenR1-SFT"
tokenizer = AutoTokenizer.from_pretrained(repo_id)
model = AutoModelForCausalLM.from_pretrained(repo_id, dtype=torch.bfloat16, device_map="auto")
messages = [
{"role": "system", "content": 'Please reason step by step, and put your final answer within \\boxed{}.'},
{"role": "user", "content": "Solve 2x + 3 = 11."},
]
inputs = tokenizer.apply_chat_template(messages, tokenize=True, add_generation_prompt=True, return_dict=True, return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=3072, do_sample=True, temperature=0.6, top_p=0.95, eos_token_id=[151643, 151645], pad_token_id=151643)
print(tokenizer.decode(outputs[0, inputs["input_ids"].shape[1]:], skip_special_tokens=True))
Study collection and subsequent GRPO stage
This repository contains final SFT weights. Subsequent GRPO checkpoints are published separately in the same study collection after their runs finish. The subsequent RL dataset is zbeeb/Staleness-GRPO-DAPO-Math-17k.
provenance.json, training-config.json, and export-manifest.json record the source model and dataset revisions, training recipe, completion evidence, artifact sizes, and SHA-256 checksums. Optimizer states and recovery checkpoints are not included.
License and attribution
The upstream license is retained verbatim in LICENSE; attribution and modification notices are in Notice. This fine-tuned model is distributed under the same upstream model license.