AceReason-Nemotron 1.1: Advancing Math and Code Reasoning through SFT
  and RL Synergy
Authors: name: Zihan Liu; name: Zhuolin Yang; name: Yang Chen; name: Chankyu Lee; name: Mohammad Shoeybi; name: Bryan Catanzaro; name: Wei Ping
Published: 2025-06-16 09:27:48

Abstract: In this work, we investigate the synergy between supervised fine-tuning (SFT)
and reinforcement learning (RL) in developing strong reasoning models. We begin
by curating the SFT training data through two scaling strategies: increasing
the number of collected prompts and the number of generated responses per
prompt. Both approaches yield notable improvements in reasoning performance,
with scaling the number of prompts resulting in more substantial gains. We then
explore the following questions regarding the synergy between SFT and RL: (i)
Does a stronger SFT model consistently lead to better final performance after
large-scale RL training? (ii) How can we determine an appropriate sampling
temperature during RL training to effectively balance exploration and
exploitation for a given SFT initialization? Our findings suggest that (i)
holds true, provided effective RL training is conducted, particularly when the
sampling temperature is carefully chosen to maintain the temperature-adjusted
entropy around 0.3, a setting that strikes a good balance between exploration
and exploitation. Notably, the performance gap between initial SFT models
narrows significantly throughout the RL process. Leveraging a strong SFT
foundation and insights into the synergistic interplay between SFT and RL, our
AceReason-Nemotron-1.1 7B model significantly outperforms
AceReason-Nemotron-1.0 and achieves new state-of-the-art performance among
Qwen2.5-7B-based reasoning models on challenging math and code benchmarks,
thereby demonstrating the effectiveness of our post-training recipe. We release
the model and data at: https://huggingface.co/nvidia/AceReason-Nemotron-1.1-7B