Session
Quantization and Compression 1
Mission B4 & B15
AWQ: Activation-aware Weight Quantization for On-Device LLM Compression and Acceleration
Ji Lin · Jiaming Tang · Haotian Tang · Shang Yang · Wei-Ming Chen · Wei-Chen Wang · Guangxuan Xiao · Xingyu Dang · Chuang Gan · Song Han
Large language models (LLMs) have shown excellent performance on various tasks, but the astronomical model size raises the hardware barrier for serving (memory size) and slows down token generation (memory bandwidth). In this paper, we propose Activation-aware Weight Quantization (AWQ), a hardware-friendly approach for LLM low-bit weight-only quantization. Our method is based on the observation that weights are not equally important: protecting 1% of salient weights can greatly reduce quantization error. We then propose to search for the optimal per-channel scaling that protects the salient weights by observing the activation, not weights. AWQ does not rely on any backpropagation or reconstruction, so it can well preserve LLMs' generalization ability on different domains and modalities, without overfitting to the calibration set. AWQ outperforms existing work on various language modeling and domain-specific benchmarks. Thanks to better generalization, it achieves excellent quantization performance for instruction-tuned LMs and, for the first time, multi-modal LMs. Alongside AWQ, we implement an efficient and flexible inference framework tailored for LLMs on the edge, offering more than 3x speedup over the Huggingface FP16 implementation on both desktop and mobile GPUs. It also democratizes the deployment of the 70B LLaMA-2 model on mobile GPUs.
QMoE: Sub-1-Bit Compression of Trillion Parameter Models
Elias Frantar · Dan Alistarh
Mixture-of-Experts (MoE) architectures offer a general solution to the high inference costs of large language models (LLMs) via sparse routing, bringing faster and more accurate models, at the cost of massive parameter counts. For example, the SwitchTransformer-c2048 model has 1.6 trillion parameters, requiring 3.2TB of accelerator memory to run efficiently, which makes practical deployment challenging and expensive. In this paper, we present a solution to this memory problem, in form of a new compression and execution framework called QMoE. Specifically, QMoE consists of a scalable algorithm which accurately compresses trillion-parameter MoEs to less than 1 bit per parameter, in a custom format co-designed with bespoke GPU decoding kernels to facilitate efficient end-to-end compressed inference, with minor runtime overheads relative to uncompressed execution. Concretely, QMoE can compress the 1.6 trillion parameter SwitchTransformer-c2048 model to less than 160GB (20x compression, 0.8 bits per parameter) at only minor accuracy loss, in less than a day on a single GPU. This enables, for the first time, the execution of a trillion-parameter model on affordable commodity hardware, like a single server with 4x NVIDIA A6000 or 8x NVIDIA 3090 GPUs, at less than 5% runtime overhead relative to ideal uncompressed inference. The anonymized code is available at: github.com/mlsys24-qmoe/qmoe.
Atom: Low-Bit Quantization for Efficient and Accurate LLM Serving
Yilong Zhao · Chien-Yu Lin · Kan Zhu · Zihao Ye · Lequn Chen · Size Zheng · Luis Ceze · Arvind Krishnamurthy · Tianqi Chen · Baris Kasikci
The growing demand for Large Language Models (LLMs) in applications such as content generation, intelligentchatbots, and sentiment analysis poses considerable challenges for LLM service providers. To efficiently useGPU resources and boost throughput, batching multiple requests has emerged as a popular paradigm; to furtherspeed up batching, LLM quantization techniques reduce memory consumption and increase computing capacity.However, prevalent quantization schemes (e.g., 8-bit weight-activation quantization) cannot fully leverage thecapabilities of modern GPUs, such as 4-bit integer operators, resulting in sub-optimal performance.To maximize LLMs’ serving throughput, we introduce Atom, a low-bit quantization method that achieves highthroughput improvements with negligible accuracy loss. Atom significantly boosts serving throughput by usinglow-bit operators and considerably reduces memory consumption via low-bit quantization. It attains high accuracyby applying a novel mixed-precision and fine-grained quantization process. We evaluate Atom on 4-bit weight-activation quantization setups in the serving context. Atom improves end-to-end throughput by up to 7.73×compared to the FP16 and by 2.53× compared to INT8 quantization, while maintaining the same latency target.