Speculative decoding
FR-Spec
FR-Spec: Accelerating Large-Vocabulary Language Models via Frequency-Ranked Speculative Sampling
Superseded — cited as a baseline and beaten by newer methods
4 papers critique it · 5 beat it on benchmarks
What papers say
Verbatim critique sentences, each from a paper that cites FR-Spec as a baseline.
static methods rely on the assumption of static word frequencies and fail to capture long-tail tokens that become locally probable in specialized domains or during topic shifts
“While effective in reducing latency, these static subsets may suppress rare or domain-specific tokens, lowering acceptance in speculative decoding.”
“are context-insensitive and struggle with long-tail tokens, leading to lower acceptance rates in diverse scenarios.”
“All tokens outside this vocabulary are assigned zero probability and can never be proposed by the drafter, which typically reduces acceptance quality.”
Beaten on benchmarks
Head-to-head results where a newer method reports beating FR-Spec. Values are copied from the source paper's tables — verify against the cited paper.
SlimSpec beats FR-Spec
2.40 vs 2.07
Speedup · [Llama3.1-8B-Instruct, temperature 1, batch size 1]
SlimSpec: Low-Rank Draft LM-Head for Accelerated Speculative DecodingEvoSpec beats FR-Spec
133.31 vs 117.43
Avg throughput (tokens/s) · [Llama-3.2-1B (Draft) / Llama-3.2-3B (Target), Static 32k + Dyna 256]
EvoSpec: Evolving Speculative Decoding via Real-Time Vocabulary and Parameter AdaptationTargetDomino beats FR-Spec
2.44 vs 2.17
Speedup at concurrency=4 · [LiveCodeBench, Concurrency]
Domino: Decoupling Causal Modeling from Autoregressive Drafting in Speculative DecodingNanoSpec beats FR-Spec
392.7 vs 369.7
Speed · [Llama-3.1-8B-Instruct with EAGLE-2]
MicroSpec: Accelerating Speculative Decoding with Lightweight In-Context VocabulariesDynaSpec beats FR-Spec
94.98 vs 89.83
Average · [Llama-3-8B-Instruct]
DynaSpec: Context-aware Dynamic Speculative Sampling for Large-Vocabulary 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Recent methods in the same sub-problem, not yet superseded in the knowledge base — arXiv benchmark leaders, not vetted production recommendations.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 11, 2026
- EvoSpecEvoSpec: Evolving Speculative Decoding via Real-Time Vocabulary and Parameter AdaptationTargetApr 17, 2026
- Apr 8, 2026