## Introduction
PARD is a high-performance speculative decoding method that also enables low-cost adaptation of autoregressive draft models into parallel draft models. It offers the following advantages:
- **Low-Cost Training**: PARD adapts AR (autoregressive) draft models into parallel draft models with minimal overhead. Compared to pure AR draft models, PARD achieves an average inference speedup of 1.78×. By introducing a conditional drop-token strategy, PARD improves training efficiency by up to 3× while maintaining the same level of accuracy.
- **Generalizability**: Thanks to its target-independent design, a single PARD draft model can accelerate an entire family of target models. This contrasts with target-dependent approaches such as Medusa and EAGLE, which require retraining or tuning for each new target. As a result, PARD significantly reduces both deployment complexity and adaptation cost.
- **High Performance**: When integrated into an optimized inference framework called Transformers+ PARD delivers up to a 4.08× speedup, with LLaMA3.1 8B reaches a state-of-the-art 311.5 tokens per second. When integrated into vLLM, PARD delivers up to 3.06× speedup, outperforming other speculative decoding methods in vLLM by 1.51×.
AR and AR+ represent baseline auto-regressive generation using Transformers and Transformers+, respectively. VSD denotes vanilla speculative decoding. PARD refers to the proposed method in this work.
## Model Weights
| Model Series | Model Name | Download |
|--------------|---------------------------------------|---------------|
| llama3 | PARD-Llama-3.2-1B | [🤗 HuggingFace](https://huggingface.co/amd/PARD-Llama-3.2-1B) |
| DSR Qwen | PARD-DeepSeek-R1-Distill-Qwen-1.5B | [🤗 HuggingFace](https://huggingface.co/amd/PARD-DeepSeek-R1-Distill-Qwen-1.5B) |
| Qwen | PARD-Qwen2.5-0.5B | [🤗 HuggingFace](https://huggingface.co/amd/PARD-Qwen2.5-0.5B) |
## How To Use
Please visit [PARD](https://github.com/AMD-AIG-AIMA/PARD) repo for more information
## Citation
```
@article{an2025pard,
title={PARD: Accelerating LLM Inference with Low-Cost PARallel Draft Model Adaptation},
author={An, Zihao and Bai, Huajun and Liu, Ziqiong and Li, Dong and Barsoum, Emad},
journal={arXiv preprint arXiv:2504.18583},
year={2025}
}
```
