Xmodel-2.5: 1.3B Data-Efficient Reasoning SLM
To address the challenges of deploying large language models (LLMs) on resource-constrained edge devices and cost-sensitive settings, this paper proposes an efficient small language model (SLM) with 1.3 billion parameters. The method integrates three key innovations: (1) micro-parameterization (μP) to enable hyperparameter transfer across model scales; (2) a three-phase training paradigm—Warmup–Stable–Decay—with a switch to the Muon optimizer during the Decay phase; and (3) architectural and systems optimizations, including tied word embeddings, FP8 mixed-precision training, and large-scale pretraining. Evaluated on 13 reasoning benchmarks, the model achieves an average improvement of +4.58% over baseline SLMs, while remaining deployable on edge hardware. All training code and checkpoints are publicly released.