SmallThinker: A Family of Efficient Large Language Models Natively
  Trained for Local Deployment
Authors: name: Yixin Song; name: Zhenliang Xue; name: Dongliang Wei; name: Feiyang Chen; name: Jianxiang Gao; name: Junchen Liu; name: Hangyu Liang; name: Guangshuo Qin; name: Chengrong Tian; name: Bo Wen; name: Longyu Zhao; name: Xinrui Zheng; name: Zeyu Mi; name: Haibo Chen
Published: 2025-07-28 16:45:14

Abstract: While frontier large language models (LLMs) continue to push capability
boundaries, their deployment remains confined to GPU-powered cloud
infrastructure. We challenge this paradigm with SmallThinker, a family of LLMs
natively designed - not adapted - for the unique constraints of local devices:
weak computational power, limited memory, and slow storage. Unlike traditional
approaches that mainly compress existing models built for clouds, we architect
SmallThinker from the ground up to thrive within these limitations. Our
innovation lies in a deployment-aware architecture that transforms constraints
into design principles. First, We introduce a two-level sparse structure
combining fine-grained Mixture-of-Experts (MoE) with sparse feed-forward
networks, drastically reducing computational demands without sacrificing model
capacity. Second, to conquer the I/O bottleneck of slow storage, we design a
pre-attention router that enables our co-designed inference engine to prefetch
expert parameters from storage while computing attention, effectively hiding
storage latency that would otherwise cripple on-device inference. Third, for
memory efficiency, we utilize NoPE-RoPE hybrid sparse attention mechanism to
slash KV cache requirements. We release SmallThinker-4B-A0.6B and
SmallThinker-21B-A3B, which achieve state-of-the-art performance scores and
even outperform larger LLMs. Remarkably, our co-designed system mostly
eliminates the need for expensive GPU hardware: with Q4_0 quantization, both
models exceed 20 tokens/s on ordinary consumer CPUs, while consuming only 1GB
and 8GB of memory respectively. SmallThinker is publicly available at
hf.co/PowerInfer/SmallThinker-4BA0.6B-Instruct and
hf.co/PowerInfer/SmallThinker-21BA3B-Instruct.