LLM quantization
PB-LLM
PB-LLM: Partially Binarized Large Language Models
Superseded baseline#11 of 80 most-superseded · first seen Sep 29, 2023
Superseded — cited as a baseline and beaten by newer methods
4 papers critique it · 3 beat it on benchmarks
What papers say
Verbatim critique sentences, each from a paper that cites PB-LLM as a baseline.
However, it reveals the challenge of retaining a significant portion of weights, typically over 30%, at INT8 precision to maintain acceptable performance.
“both methods introduce additional unstructured fine-grained masks to distinguish salient weights which requires additional 1-bit per weight to store the mask and leads the memory of the quantized model to exceeding 2-bit per weight, where PB-LLM with 2.7-bit and BiLLM with 2.1-bit respectively”
“Even the recent binary PTQ method for LLMs, PB-LLM~shang2023pb, only maintains a perplexity metric of around 800 with an average weight of 1.7 bits.”
“PB-LLM~shang2023pb applies fixed saliency thresholds across layers”
Beaten on benchmarks
Head-to-head results where a newer method reports beating PB-LLM. Values are copied from the source paper's tables — verify against the cited paper.
PTQ1.61 beats PB-LLM
12.50 vs 102.19
BiLLM beats PB-LLM
8.41 vs 28.37
perplexity · [LLaMA2-70B mixed-bit]
BiLLM: Pushing the Limit of Post-Training Quantization for LLMsAMQ beats PB-LLM
67.05 vs 46.55
Avg. · [Llama 2 13B, 2.5-bit]
AMQ: Enabling AutoML for Mixed-precision Weight-Only Quantization of Large Language Models
What to use instead
Recent methods in the same sub-problem, not yet superseded in the knowledge base — arXiv benchmark leaders, not vetted production recommendations.
- May 29, 2026
- LFQLFQ: Logit-aware Final-block Quantization for Boosting the Generation Quality of Low-Bit Quantized LLMsMay 28, 2026
- ADMM-QADMM-Q: An Improved Hessian-based Weight Quantizer for Post-Training Quantization of Large Language ModelsMay 11, 2026
- May 6, 2026
- Apr 11, 2026
- Jan 21, 2026
- Grouped Lattice Vector Quantization (GLVQ)Learning Grouped Lattice Vector Quantizers for Low-Bit LLM CompressionOct 23, 2025
- Sep 28, 2025
- Bi-VLMBi-VLM: Pushing Ultra-Low Precision Post-Training Quantization Boundaries in Vision-Language ModelsSep 23, 2025
- Sep 18, 2025