In plain words: Each weight is limited to just -1, 0, or 1 instead of the usual long decimal numbers, making the model much cheaper to run. It matched full-precision models of the same size and training on accuracy while using less memory and energy.
Abstract · The Era of 1-bit LLMs: All Large Language Models are in 1.58 Bits
Recent research, such as BitNet, is paving the way for a new era of 1-bit Large Language Models (LLMs). In this work, we introduce a 1-bit LLM variant, namely BitNet b1.58, in which every single parameter (or weight) of the LLM is ternary {-1, 0, 1}. It matches the full-precision (i.e., FP16 or BF16) Transformer LLM with the same model size and training tokens in terms of both perplexity and end-task performance, while being significantly more cost-effective in terms of latency, memory, throughput, and energy consumption. More profoundly, the 1.58-bit LLM defines a new scaling law and recipe for training new generations of LLMs that are both high-performance and cost-effective. Furthermore, it enables a new computation paradigm and opens the door for designing specific hardware optimized for 1-bit LLMs.
Shuming Ma, Hongyu Wang, Lingxiao Ma, Lei Wang, Wenhui Wang, Shaohan Huang, Li Dong, Ruiping Wang, Jilong Xue, Furu Wei
arXiv:2402.17764 · cs.CL, cs.LG · submitted Feb 27, 2024
abstract · pdf · html · Work in progress
* In existing LLMs, we can replace all parameter floating-point values representing real numbers with ternary values representing (-1, 0, 1).
* In matrix multiplications (e.g., weights by vectors), we can replace elementwise products in each dot product (a₁b₁ + a₂b₂ ...) with elementwise additions (a₁+b₁ + a₂+b₂ ...), in which signs depend on each value. See the paper for exact details.
On existing hardware, the gains in compute and memory efficiency are significant, without performance degradation (as tested by the authors).
If the proposed methods are implemented in hardware, we will see even greater gains in compute and memory efficiency.
Wow.