shanyangmie/physics-r1-seed17-v4-step60-fsdp
Physics-R1 — Seed 17, v4 step-60 (FSDP-sharded)
**Project Page** | **Paper** | **Code** | **Training corpus**
Physics-R1 fine-tune of Qwen3-VL-8B-Thinking on the audited `PhysR1Corp` (2,268 closed-form physics problems) via full-parameter FSDP1 GRPO with binary correctness reward. This is the seed-17 v4 (audited-data) re-validation checkpoint at step 60.
Released alongside Physics-R1: An Audited Olympiad Corpus and Recipe for Visual Physics Reasoning.
Which checkpoint should you use?
On the relationship to Table 2: the paper's seed-17 row (PhysReason 43.1, PhysOlym-A 25.0, PhyX-3k 77.2, ...) is from the canonical step-63 checkpoint. This v4 step-60 checkpoint is a re-validation on the audited 2,268-record PhysR1Corp; its step-60 mean tracks the canonical mean within statistical noise. For exact paper-reproduction numbers, use the canonical checkpoint.
Training recipe
- Base model: `Qwen/Qwen3-VL-8B-Thinking`
- Algorithm: GRPO (verl 0.6.1, full-parameter FSDP1 —
actor.strategy=fsdp, notfsdp2; FSDP2 fails on Qwen3-VL visual encoder device placement) - Reward: binary correctness, per-subpart Sonnet judge with problem-level AND aggregation (see paper §3.2)
- Data: `shanyangmie/physr1corp` — 2,268 audited closed-form problems
- Seed / step: 17 / 60
- Hardware: 4×H200 (FSDP1 4-way sharded)
Full hyperparameters are in the paper appendix.
Format: verl FSDP-sharded checkpoint (conversion required)
This checkpoint is saved in verl's FSDP-sharded format, not safetensors. It is not directly loadable via AutoModelForImageTextToText.from_pretrained without a merge step.
File layout
actor/
├── huggingface/ # HF-style config + tokenizer
│ ├── config.json
│ ├── tokenizer.json, merges.txt, vocab.json
│ ├── preprocessor_config.json
│ └── ...
├── model_world_size_4_rank_{0,1,2,3}.pt # 4-way FSDP weight shards (~8.7 GB each, ~35 GB total)
├── optim_world_size_4_rank_{0,1,2,3}.pt # optimizer state (~17.5 GB each, not needed for inference)
├── extra_state_world_size_4_rank_{0..3}.pt
└── fsdp_config.json
data.pt # verl bookkeeping (not needed for inference)Convert to HF safetensors
Use verl's model_merger.py:
git clone https://github.com/volcengine/verl
cd verl
# Download only the inference-required files (skips ~70 GB of optimizer state)
huggingface-cli download shanyangmie/physics-r1-seed17-v4-step60-fsdp \
--include "actor/model_world_size_4_rank_*.pt" \
--include "actor/huggingface/*" \
--include "actor/fsdp_config.json" \
--include "actor/extra_state_world_size_4_rank_*.pt" \
--local-dir ./ckpt
# Merge FSDP shards into HF safetensors
python scripts/model_merger.py merge \
--backend fsdp \
--hf_model_path Qwen/Qwen3-VL-8B-Thinking \
--local_dir ./ckpt/actor \
--target_dir ./physics-r1-seed17-v4-step60-hfThen load with standard HF:
from transformers import AutoModelForImageTextToText, AutoProcessor
model = AutoModelForImageTextToText.from_pretrained(
"./physics-r1-seed17-v4-step60-hf",
torch_dtype="bfloat16",
device_map="auto",
)
processor = AutoProcessor.from_pretrained("./physics-r1-seed17-v4-step60-hf")License
Apache 2.0, inheriting from the base model `Qwen3-VL-8B-Thinking`. Training data (physr1corp) is CC BY-NC 4.0, so this derivative checkpoint is intended for non-commercial research use.
Citation
@misc{yang2026physicsr1,
title = {Physics-R1: An Audited Olympiad Corpus and Recipe for Visual Physics Reasoning},
author = {Yang, Shan},
year = {2026},
url = {https://huggingface.co/papers/2605.14040}
}