Quantize the Target, Quantize the Drafter: Efficient Inference with Qwen3.5-4B
This work addresses the challenge of achieving low-latency inference for the Qwen3.5-4B model on resource-constrained NVIDIA A10G GPUs by proposing an efficient approach that integrates quantization with speculative decoding. The method employs quantization-aware distillation to recover model accuracy and introduces a two-stage training strategy to construct a block-wise diffusion draft model specifically tailored for the quantized target model. Furthermore, the draft model is enhanced with quantization and sliding window attention to improve long-context decoding efficiency while maintaining a high token acceptance rate. Experimental results demonstrate that, under strict quality constraints, the proposed method achieves an average speedup of 6.98× over the baseline and secured third place in a related competition.