We present Ring-lite, a Mixture-of-Experts (MoE)-based large language model optimized via reinforcement learning (RL) to achieve efficient and robust reasoning capabilities. Built upon the publicly available Ling-lite model, a 16.8 billion parameter model with 2.75 billion activated parameters, our approach matches the performance of state-of-the-art (SOTA) small-scale reasoning models on challenging benchmarks (e.g., AIME, LiveCodeBench, GPQA-Diamond) while activating only one-third of the parameters required by comparable models. To accomplish this, we introduce a joint training pipeline integrating distillation with RL, revealing undocumented challenges in MoE RL training. First, we identify optimization instability during RL training, and we propose Constrained Contextual Computation Policy Optimization(C3PO), a novel approach that enhances training stability and improves computational throughput via algorithm-system co-design methodology. Second, we empirically demonstrate that selecting distillation checkpoints based on entropy loss for RL training, rather than validation metrics, yields superior performance-efficiency trade-offs in subsequent RL training. Finally, we develop a two-stage training paradigm to harmonize multi-domain data integration, addressing domain conflicts that arise in training with mixed dataset. We will release the model, dataset, and code.
View on arXiv@article{team2025_2506.14731,
title={ Ring-lite: Scalable Reasoning via C3PO-Stabilized Reinforcement Learning for LLMs },
author={ Ling Team and Bin Hu and Cai Chen and Deng Zhao and Ding Liu and Dingnan Jin and Feng Zhu and Hao Dai and Hongzhi Luan and Jia Guo and Jiaming Liu and Jiewei Wu and Jun Mei and Jun Zhou and Junbo Zhao and Junwu Xiong and Kaihong Zhang and Kuan Xu and Lei Liang and Liang Jiang and Liangcheng Fu and Longfei Zheng and Qiang Gao and Qing Cui and Quan Wan and Shaomian Zheng and Shuaicheng Li and Tongkai Yang and Wang Ren and Xiaodong Yan and Xiaopei Wan and Xiaoyun Feng and Xin Zhao and Xinxing Yang and Xinyu Kong and Xuemin Yang and Yang Li and Yingting Wu and Yongkang Liu and Zhankai Xu and Zhenduo Zhang and Zhenglei Zhou and Zhenyu Huang and Zhiqiang Zhang and Zihao Wang and Zujie Wen },
journal={arXiv preprint arXiv:2506.14731},
year={ 2025 }
}