Speculative decoding
PLD
PLD+: Accelerating LLM inference by leveraging Language Model Artifacts
Superseded — cited as a baseline and beaten by newer methods
7 papers critique it · 13 beat it on benchmarks
What papers say
Verbatim critique sentences, each from a paper that cites PLD as a baseline.
existing model-free approaches, such as prompt-lookup decoding (PLD)~saxena2023prompt, achieve low overhead and rapid token generation, but typically lack adaptivity.
“there are no matched tokens in more than 30% of decoding steps in PLD”
“These training-free approaches are highly effective for tasks with high repetition (e.g., code editing) but struggle with open-ended generation where context reuse is minimal.”
“pattern-repeating scenarios such as code generation, but can only propose a single continuation at a time. Moreover, because pattern matches are sparse and fail to capture the full diversity of target model outputs, PLD is constrained to specific domains and cannot generalize broadly.”
“Prompt- and retrieval-based approaches (PLD, Lookahead, CLLMs) improve draft quality but degrade with scarce context”
“PLD~pld-saxena-2023 focuses on current text while REST~rest-he-2024 uses a text corpus.”
“However, it cannot predict new tokens or their combinations.”
Beaten on benchmarks
Head-to-head results where a newer method reports beating PLD. Values are copied from the source paper's tables — verify against the cited paper.
RASD beats PLD
3.48 vs 0.45
tau · [L 8B, Temperature = 1]
RASD: Retrieval-Augmented Speculative DecodingSpecUCB beats PLD
4.35 vs 1.53
MAT · [LLaMA3-8B-Instruct, Alpaca]
BanditSpec: Adaptive Speculative Decoding via Bandit AlgorithmsSpeculative Sampling beats PLD
2.42 vs 1.06
Avg · [T=0.0 (greedy decoding)]
Towards Fast Multilingual LLM Inference: Speculative Decoding and Specialized DraftersSAM-Decoding beats PLD
3.35 vs 1.52
Speedup · [HumanEval]
SAM Decoding: Speculative Decoding via Suffix AutomatonToolSpec beats PLD
4.19 vs 2.12
Overall Speedup · [LLaMA-3.1-8B-Instruct]
ToolSpec: Accelerating Tool Calling via Schema-Aware and Retrieval-Augmented Speculative DecodingOWL beats PLD
4.27 vs 2.24
acceptance_length · [Llama-3.3-70B-Instruct]
OWL: Overcoming Window Length-Dependence in Speculative Decoding for Long-Context InputsRACER beats PLD
2.52 vs 1.49
Speedup · [Vicuna 33B]
RACER: Retrieval-Augmented Contextual Rapid Speculative DecodingDART beats PLD
2.85 vs 1.74
Speedup · [L2 7B Temperature=0]
DART: Diffusion-Inspired Speculative Decoding for Fast LLM InferenceDiffuSpec beats PLD
3.08 vs 1.93
Speedup · [training-free block, Qwen2.5-32B target]
DiffuSpec: Unlocking Diffusion Language Models for Speculative DecodingLogitSpec beats PLD
2.41 vs 1.60
DuoDec beats PLD
2.61 vs 2.10
speedup (φ) · [Llama2-7b]
DuoDecoding: Hardware-aware Heterogeneous Speculative Decoding with Dynamic Multi-Sequence DraftingCAS-Spec beats PLD
1.481 vs 1.385
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.
- Collaborative Speculative Decoding (CoSpec)Beyond the Target: From Imitation to Collaboration in Speculative DecodingMay 24, 2026
- ToolSpecToolSpec: Accelerating Tool Calling via Schema-Aware and Retrieval-Augmented Speculative DecodingApr 15, 2026
- QuasarQuasar: Quantized Self-Speculative Acceleration for Rapid Inference via Memory-Efficient VerificationMar 2, 2026
- FLy (Training-Free Loosely Speculative Decoding)Training-Free Loosely Speculative Decoding: Accepting Semantically Correct Drafts Beyond Exact MatchNov 28, 2025
- Nov 1, 2025
- Oct 30, 2025
- Oct 22, 2025
- Oct 8, 2025
- Group Tree Optimization (GTO)Bridging Draft Policy Misalignment: Group Tree Optimization for Speculative DecodingSep 26, 2025
- Sep 22, 2025