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1
- ---
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- base_model: incoai/Qwen3.8-27B-DFlash2
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- tags:
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- - transformers
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- - safetensors
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- - qwen3
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- - dflash2
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- - speculative-decoding
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- - block-diffusion
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- - draft-model
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- - sglang
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- - vllm
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- - text-generation
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- - base_model:Qwen/Qwen3.8-27B
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- - base_model:finetune:Qwen/Qwen3.8-27B
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- - license:apache-2.0
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- - text-generation-inference
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- - region:us
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- ---
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-
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- # Qwen 3.8 27B DFlash2 GGUF
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-
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- GGUF quantizations of [**Inco AI DFlash2 draft model**](https://huggingface.co/incoai/Qwen3.8-27B-DFlash2) for [**Qwen 3.8 27B**](https://huggingface.co/Qwen/Qwen3.8-27B).
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-
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- Use with [BeeLlama.cpp](https://github.com/Anbeeld/beellama.cpp), a llama.cpp fork with advanced quantization features.
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-
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- ## Benchmark results
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-
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- ### Machine configuration
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-
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- - OS: Windows 11 Pro
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- - CPU: AMD Ryzen 9 9950X 16-Core Processor
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- - GPU: NVIDIA GeForce RTX 3090
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- - Server CPU thread pool: 16 threads
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-
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- ### Test setup
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-
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- - Runtime: [BeeLlama.cpp v0.4.4](https://github.com/Anbeeld/beellama.cpp), CUDA 13.1
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- - Target model: [Qwen3.8-27B-UD-Q4_K_M](https://huggingface.co/unsloth/Qwen3.8-27B-GGUF)
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- - 15 generations per each prompt + quant pair
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- - DFlash2 setup: 7 draft tokens per block
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- - Context: 8192 tokens
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- - Batch size 4096, micro-batch size 1024
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- - Temperature 1.0, top-p 0.95, top-k 20
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- - Reasoning disabled
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-
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- ### Task store module
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-
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- <details>
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- <summary>Show prompt</summary>
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-
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- ```text
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- Write one complete Python 3 file using only the standard library.
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-
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- Return only Python code. Do not use markdown, comments, tests, examples, or explanatory text.
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-
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- Implement a deterministic Task store module with a compact, repetitive structure that is easy to predict.
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-
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- Required shape:
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- - imports: dataclasses, datetime, typing
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- - dataclass Task with fields id: int, title: str, status: str, created_at: str
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- - class TaskStore with an internal dict[int, Task]
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- - methods: add, get, rename, mark_done, reopen, delete, clear, list_all, list_open, list_done, count_open, count_done, titles, to_dicts, __len__, __contains__
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- - add assigns increasing integer ids starting at 1
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- - valid statuses are "open" and "done"
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- - all list methods return tasks sorted by id
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- - count_open and count_done use explicit loops
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- - titles returns task titles sorted by task id
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- - to_dicts returns deterministic dictionaries sorted by id
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- - to_dicts includes id, title, status, and created_at keys for every task
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- - raise ValueError for empty title or missing task id
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- - use straightforward if statements and explicit loops
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- - keep method bodies short and similar in style
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- - no argparse, no JSON, no file IO, no unittest, no pytest
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- - target about 110 to 132 lines of code
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- - define __all__ = ["Task", "TaskStore"]
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- - stop immediately after defining __all__
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- ```
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-
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- </details>
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-
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- | Quant type | Size (MB) | Mean length | Median tok/s | Mean tok/s | Median AR | Mean AR |
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- |---|---:|---:|---:|---:|---:|---:|
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- | Baseline | n/a | 897.93 | 42.222 | 42.237 | n/a | n/a |
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- | Q2_K | 705.43 | 891.20 | 109.128 | 109.079 | 0.912 | 0.913 |
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- | Q3_K_M | 916.70 | 891.20 | 108.330 | 108.747 | 0.916 | 0.915 |
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- | Q4_K_M | 1,143.01 | 893.00 | 108.123 | 107.906 | 0.910 | 0.908 |
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- | Q5_K_M | 1,359.93 | 899.87 | 107.408 | 107.332 | 0.906 | 0.907 |
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- | Q6_K | 1,590.41 | 906.80 | 106.738 | 107.123 | 0.895 | 0.900 |
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- | Q8_0 | 2,056.41 | 890.93 | 109.767 | 109.067 | 0.916 | 0.911 |
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- | bf16 | 3,860.29 | 899.47 | 108.508 | 108.468 | 0.915 | 0.914 |
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-
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- ### Key-value report module
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-
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- <details>
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- <summary>Show prompt</summary>
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-
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- ```text
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- Write one complete Python 3 file using only the standard library.
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-
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- Return only Python code. Do not use markdown, comments, tests, examples, or explanatory text.
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-
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- Implement a deterministic KV report module with a compact, repetitive structure that is easy to predict.
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-
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- Required shape:
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- - imports: dataclasses, typing
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- - dataclass Row with fields key: str, value: str
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- - class Report with an internal list[Row]
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- - methods: add, set, get, delete, clear, keys, values, items, sorted_rows, render_lines, render_text, render_csv, filter_prefix, update_many, to_dict, copy, count_prefix, first_key, __len__, __contains__
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- - add appends a new row and rejects duplicate keys
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- - set updates an existing row or appends a new row
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- - get returns the value for a key
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- - delete removes a row by key
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- - keys, values, and items preserve insertion order
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- - sorted_rows returns rows sorted by key
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- - render_lines returns strings formatted as "key: value"
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- - render_text joins render_lines with newline characters
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- - render_csv returns deterministic "key,value" lines with a header
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- - filter_prefix returns a new Report containing keys that start with the prefix
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- - update_many applies set for each key and value in a dictionary sorted by key
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- - to_dict returns a deterministic dictionary sorted by key
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- - copy returns a new Report with the same rows in the same order
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- - count_prefix returns the number of keys that start with the prefix using an explicit loop
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- - first_key returns the first key and raises ValueError when there are no rows
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- - raise ValueError for empty keys, duplicate keys, or missing keys
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- - use straightforward if statements and explicit loops
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- - keep method bodies short and similar in style
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- - no enum, no alignment modes, no markdown table, no textwrap, no itertools, no unittest, no pytest
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- - target about 130 to 155 lines of code
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- - define __all__ = ["Row", "Report"]
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- - stop immediately after defining __all__
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- ```
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-
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- </details>
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-
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- | Quant type | Size (MB) | Mean length | Median tok/s | Mean tok/s | Median AR | Mean AR |
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- |---|---:|---:|---:|---:|---:|---:|
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- | Baseline | n/a | 1,026.60 | 41.865 | 41.829 | n/a | n/a |
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- | Q2_K | 705.43 | 980.80 | 105.876 | 105.453 | 0.888 | 0.886 |
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- | Q3_K_M | 916.70 | 1,007.53 | 105.543 | 105.158 | 0.885 | 0.883 |
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- | Q4_K_M | 1,143.01 | 1,002.20 | 106.475 | 105.659 | 0.895 | 0.890 |
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- | Q5_K_M | 1,359.93 | 1,003.00 | 104.483 | 104.082 | 0.886 | 0.883 |
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- | Q6_K | 1,590.41 | 1,022.80 | 107.050 | 106.483 | 0.900 | 0.894 |
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- | Q8_0 | 2,056.41 | 992.40 | 108.184 | 108.047 | 0.893 | 0.895 |
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- | bf16 | 3,860.29 | 1,001.47 | 103.355 | 103.295 | 0.874 | 0.878 |
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-
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- ---
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-
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-
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- # Qwen3.8-27B-DFlash2
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-
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- [Blog](https://inco.ai/blog/dflash2/) | [GitHub](https://github.com/z-lab/dflash)
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-
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- This repository contains the DFlash 2 draft model for
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- [`Qwen/Qwen3.8-27B`](https://huggingface.co/Qwen/Qwen3.8-27B).
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- It is not a standalone language model: it runs inside a speculative
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- decoding server and drafts tokens for the target model to verify. The checkpoint is also
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- mirrored at [`z-lab/Qwen3.8-27B-DFlash2`](https://huggingface.co/z-lab/Qwen3.8-27B-DFlash2).
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-
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- DFlash 2 is a block-diffusion drafter for speculative decoding. It predicts
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- a whole block of tokens in a single pass and keeps the top candidates at
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- every position. A lightweight selector then traces one coherent path through them.
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- Two-tap dynamic convolutions in the backbone keep the draft from decaying
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- toward the end of the block. Decoding is lossless: greedy output
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- matches the target model exactly, and sampling preserves its distribution.
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-
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- <div align="center">
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- <img src="https://huggingface.co/incoai/Qwen3.8-27B-DFlash2/resolve/main/assets/dflash2-figure.png" alt="DFlash 2: parallel block drafting with a candidate path selector" width="100%">
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- </div>
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-
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- ## Quick Start
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-
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- Serve with [SGLang](https://github.com/sgl-project/sglang):
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-
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- ```bash
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- pip install "sglang[all] @ git+https://github.com/sgl-project/sglang.git#subdirectory=python"
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-
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- python -m sglang.launch_server \
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- --model-path Qwen/Qwen3.8-27B \
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- --speculative-algorithm DFLASH \
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- --speculative-draft-model-path incoai/Qwen3.8-27B-DFlash2 \
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- --speculative-num-draft-tokens 8
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- ```
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-
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- Or with [vLLM](https://github.com/vllm-project/vllm):
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-
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- ```bash
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- pip install -U "vllm @ git+https://github.com/vllm-project/vllm.git@refs/pull/52816/head"
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-
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- vllm serve Qwen/Qwen3.8-27B \
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- --speculative-config '{
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- "method": "dflash",
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- "model": "incoai/Qwen3.8-27B-DFlash2",
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- "num_speculative_tokens": 7
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- }'
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- ```
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-
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- See the [blog post](https://inco.ai/blog/dflash2/) for other engines and more details.
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-
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- ## Evaluation
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-
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- - Runtime: SGLang on one NVIDIA H200, with FlashAttention 3 for target and draft attention
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- - Speculation block size: 8 (7 draft tokens per verification step)
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- - Sampling: Qwen3.8's officially recommended parameters (temperature 1.0, top-p 0.95, top-k 20), with `xhigh` reasoning effort
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- - Maximum new tokens: 4096
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- - Prompts: benchmark formatting from [`z-lab/dflash`](https://github.com/z-lab/dflash)
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-
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- We compare autoregressive decoding, Qwen3.8's built-in seven-token MTP,
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- a community DSpark drafter
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- ([`RadixArk/Qwen3.8-27B-DSpark`](https://huggingface.co/RadixArk/Qwen3.8-27B-DSpark)),
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- and DFlash 2. All speculative methods propose seven draft tokens per
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- verification step.
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-
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- ### Acceptance Length
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-
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- Acceptance length is the per-request mean of completion tokens divided by verification steps.
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- Higher is better.
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-
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- | Task | MTP | DSpark | DFlash 2 |
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- | :--- | ---: | ---: | ---: |
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- | GSM8K | 5.02 | 4.36 | **5.46** |
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- | MATH-500 | 4.72 | 3.92 | **5.28** |
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- | HumanEval | 3.91 | 3.30 | **4.39** |
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- | MBPP | 3.99 | 3.51 | **4.79** |
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- | MT-Bench | 3.74 | 3.01 | **4.10** |
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-
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- ### Throughput
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-
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- Throughput is total output tokens divided by end-to-end wall time.
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- Each cell shows `output tok/s (speedup vs. autoregressive)`.
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-
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- #### Concurrency 1
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-
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- | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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- | :--- | ---: | ---: | ---: | ---: |
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- | GSM8K | 68.9 | 178.5 (2.59×) | 185.3 (2.69×) | **236.1 (3.43×)** |
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- | MATH-500 | 69.0 | 172.8 (2.51×) | 174.5 (2.53×) | **230.7 (3.34×)** |
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- | HumanEval | 69.0 | 151.9 (2.20×) | 159.9 (2.32×) | **214.6 (3.11×)** |
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- | MBPP | 69.0 | 153.1 (2.22×) | 163.3 (2.37×) | **226.9 (3.29×)** |
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- | MT-Bench | 68.9 | 134.9 (1.96×) | 137.6 (2.00×) | **184.0 (2.67×)** |
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-
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- #### Concurrency 8
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-
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- | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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- | :--- | ---: | ---: | ---: | ---: |
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- | GSM8K | 467.2 | 1,022.1 (2.19×) | 1,040.8 (2.23×) | **1,328.7 (2.84×)** |
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- | MATH-500 | 480.0 | 1,023.5 (2.13×) | 1,025.8 (2.14×) | **1,368.3 (2.85×)** |
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- | HumanEval | 483.4 | 934.2 (1.93×) | 956.5 (1.98×) | **1,291.5 (2.67×)** |
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- | MBPP | 478.0 | 938.1 (1.96×) | 974.1 (2.04×) | **1,328.0 (2.78��)** |
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- | MT-Bench | 480.5 | 835.2 (1.74×) | 802.3 (1.67×) | **1,090.2 (2.27×)** |
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-
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- #### Concurrency 32
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-
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- | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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- | :--- | ---: | ---: | ---: | ---: |
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- | GSM8K | 1,329.8 | 1,381.1 (1.04×) | 1,506.5 (1.13×) | **1,922.5 (1.45×)** |
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- | MATH-500 | 1,505.8 | 1,415.6 (0.94×) | 1,429.0 (0.95×) | **1,951.8 (1.30×)** |
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- | HumanEval | 1,546.5 | 1,296.8 (0.84×) | 1,330.1 (0.86×) | **1,799.0 (1.16×)** |
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- | MBPP | 1,507.7 | 1,314.9 (0.87×) | 1,361.3 (0.90×) | **1,886.8 (1.25×)** |
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- | MT-Bench | 1,507.4 | 1,159.7 (0.77×) | 1,115.5 (0.74×) | **1,525.3 (1.01×)** |
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-
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- ## Citation
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-
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- If you find DFlash 2 useful, please cite:
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-
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- ```bibtex
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- @misc{inco2026dflash2,
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- title = {{DFlash 2: Keep Drafting Parallel}},
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- author = {{Inco AI}},
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- year = {2026},
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- month = {August},
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- url = {https://inco.ai/blog/dflash2/}
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- }
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- ```
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-
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- Please also cite the original DFlash paper:
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-
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- ```bibtex
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- @inproceedings{chen2026dflash,
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- title = {{DFlash: Block Diffusion for Flash Speculative Decoding}},
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- author = {Chen, Jian and Liang, Yesheng and Liu, Zhijian},
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- booktitle = {International Conference on Machine Learning (ICML)},
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- year = {2026}
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- }
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- ```
 
1
+ ---
2
+ base_model: incoai/Qwen3.8-27B-DFlash2
3
+ tags:
4
+ - transformers
5
+ - safetensors
6
+ - qwen3
7
+ - dflash2
8
+ - speculative-decoding
9
+ - block-diffusion
10
+ - draft-model
11
+ - sglang
12
+ - vllm
13
+ - text-generation
14
+ - base_model:Qwen/Qwen3.8-27B
15
+ - base_model:finetune:Qwen/Qwen3.8-27B
16
+ - license:apache-2.0
17
+ - text-generation-inference
18
+ - region:us
19
+ ---
20
+
21
+ # Qwen 3.8 27B DFlash2 GGUF
22
+
23
+ GGUF quantizations of [**Inco AI DFlash2 draft model**](https://huggingface.co/incoai/Qwen3.8-27B-DFlash2) for [**Qwen 3.8 27B**](https://huggingface.co/Qwen/Qwen3.8-27B).
24
+
25
+ Use with [BeeLlama.cpp](https://github.com/Anbeeld/beellama.cpp), a llama.cpp fork with advanced quantization features.
26
+
27
+ ## Benchmark results
28
+
29
+ ### Machine configuration
30
+
31
+ - OS: Windows 11 Pro
32
+ - CPU: AMD Ryzen 9 9950X 16-Core Processor
33
+ - GPU: NVIDIA GeForce RTX 3090
34
+ - Server CPU thread pool: 16 threads
35
+
36
+ ### Test setup
37
+
38
+ - Runtime: [BeeLlama.cpp v0.4.4](https://github.com/Anbeeld/beellama.cpp), CUDA 13.1
39
+ - Target model: [Qwen3.8-27B-UD-Q4_K_M](https://huggingface.co/unsloth/Qwen3.8-27B-GGUF)
40
+ - 15 generations per each prompt + quant pair
41
+ - DFlash2 setup: 7 draft tokens per block
42
+ - Context: 8192 tokens
43
+ - Batch size 4096, micro-batch size 1024
44
+ - Temperature 1.0, top-p 0.95, top-k 20
45
+ - Reasoning disabled
46
+
47
+ ### Task store module
48
+
49
+ <details>
50
+ <summary>Show prompt</summary>
51
+
52
+ ```text
53
+ Write one complete Python 3 file using only the standard library.
54
+
55
+ Return only Python code. Do not use markdown, comments, tests, examples, or explanatory text.
56
+
57
+ Implement a deterministic Task store module with a compact, repetitive structure that is easy to predict.
58
+
59
+ Required shape:
60
+ - imports: dataclasses, datetime, typing
61
+ - dataclass Task with fields id: int, title: str, status: str, created_at: str
62
+ - class TaskStore with an internal dict[int, Task]
63
+ - methods: add, get, rename, mark_done, reopen, delete, clear, list_all, list_open, list_done, count_open, count_done, titles, to_dicts, __len__, __contains__
64
+ - add assigns increasing integer ids starting at 1
65
+ - valid statuses are "open" and "done"
66
+ - all list methods return tasks sorted by id
67
+ - count_open and count_done use explicit loops
68
+ - titles returns task titles sorted by task id
69
+ - to_dicts returns deterministic dictionaries sorted by id
70
+ - to_dicts includes id, title, status, and created_at keys for every task
71
+ - raise ValueError for empty title or missing task id
72
+ - use straightforward if statements and explicit loops
73
+ - keep method bodies short and similar in style
74
+ - no argparse, no JSON, no file IO, no unittest, no pytest
75
+ - target about 110 to 132 lines of code
76
+ - define __all__ = ["Task", "TaskStore"]
77
+ - stop immediately after defining __all__
78
+ ```
79
+
80
+ </details>
81
+
82
+ | Quant type | Size (MB) | Mean length | Median tok/s | Mean tok/s | Median AR | Mean AR |
83
+ |---|---:|---:|---:|---:|---:|---:|
84
+ | Baseline | n/a | 897.93 | 42.222 | 42.237 | n/a | n/a |
85
+ | Q2_K | 705.43 | 891.20 | 109.128 | 109.079 | 0.912 | 0.913 |
86
+ | Q3_K_M | 916.70 | 891.20 | 108.330 | 108.747 | 0.916 | 0.915 |
87
+ | Q4_K_M | 1,143.01 | 893.00 | 108.123 | 107.906 | 0.910 | 0.908 |
88
+ | Q5_K_M | 1,359.93 | 899.87 | 107.408 | 107.332 | 0.906 | 0.907 |
89
+ | Q6_K | 1,590.41 | 906.80 | 106.738 | 107.123 | 0.895 | 0.900 |
90
+ | Q8_0 | 2,056.41 | 890.93 | 109.767 | 109.067 | 0.916 | 0.911 |
91
+ | bf16 | 3,860.29 | 899.47 | 108.508 | 108.468 | 0.915 | 0.914 |
92
+
93
+ ### Key-value report module
94
+
95
+ <details>
96
+ <summary>Show prompt</summary>
97
+
98
+ ```text
99
+ Write one complete Python 3 file using only the standard library.
100
+
101
+ Return only Python code. Do not use markdown, comments, tests, examples, or explanatory text.
102
+
103
+ Implement a deterministic KV report module with a compact, repetitive structure that is easy to predict.
104
+
105
+ Required shape:
106
+ - imports: dataclasses, typing
107
+ - dataclass Row with fields key: str, value: str
108
+ - class Report with an internal list[Row]
109
+ - methods: add, set, get, delete, clear, keys, values, items, sorted_rows, render_lines, render_text, render_csv, filter_prefix, update_many, to_dict, copy, count_prefix, first_key, __len__, __contains__
110
+ - add appends a new row and rejects duplicate keys
111
+ - set updates an existing row or appends a new row
112
+ - get returns the value for a key
113
+ - delete removes a row by key
114
+ - keys, values, and items preserve insertion order
115
+ - sorted_rows returns rows sorted by key
116
+ - render_lines returns strings formatted as "key: value"
117
+ - render_text joins render_lines with newline characters
118
+ - render_csv returns deterministic "key,value" lines with a header
119
+ - filter_prefix returns a new Report containing keys that start with the prefix
120
+ - update_many applies set for each key and value in a dictionary sorted by key
121
+ - to_dict returns a deterministic dictionary sorted by key
122
+ - copy returns a new Report with the same rows in the same order
123
+ - count_prefix returns the number of keys that start with the prefix using an explicit loop
124
+ - first_key returns the first key and raises ValueError when there are no rows
125
+ - raise ValueError for empty keys, duplicate keys, or missing keys
126
+ - use straightforward if statements and explicit loops
127
+ - keep method bodies short and similar in style
128
+ - no enum, no alignment modes, no markdown table, no textwrap, no itertools, no unittest, no pytest
129
+ - target about 130 to 155 lines of code
130
+ - define __all__ = ["Row", "Report"]
131
+ - stop immediately after defining __all__
132
+ ```
133
+
134
+ </details>
135
+
136
+ | Quant type | Size (MB) | Mean length | Median tok/s | Mean tok/s | Median AR | Mean AR |
137
+ |---|---:|---:|---:|---:|---:|---:|
138
+ | Baseline | n/a | 1,026.60 | 41.865 | 41.829 | n/a | n/a |
139
+ | Q2_K | 705.43 | 980.80 | 105.876 | 105.453 | 0.888 | 0.886 |
140
+ | Q3_K_M | 916.70 | 1,007.53 | 105.543 | 105.158 | 0.885 | 0.883 |
141
+ | Q4_K_M | 1,143.01 | 1,002.20 | 106.475 | 105.659 | 0.895 | 0.890 |
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+ | Q5_K_M | 1,359.93 | 1,003.00 | 104.483 | 104.082 | 0.886 | 0.883 |
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+ | Q6_K | 1,590.41 | 1,022.80 | 107.050 | 106.483 | 0.900 | 0.894 |
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+ | Q8_0 | 2,056.41 | 992.40 | 108.184 | 108.047 | 0.893 | 0.895 |
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+ | bf16 | 3,860.29 | 1,001.47 | 103.355 | 103.295 | 0.874 | 0.878 |
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+
147
+ ---
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+
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+
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+ # Qwen3.8-27B-DFlash2
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+
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+ [Blog](https://inco.ai/blog/dflash2/) | [GitHub](https://github.com/z-lab/dflash)
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+
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+ This repository contains the DFlash 2 draft model for
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+ [`Qwen/Qwen3.8-27B`](https://huggingface.co/Qwen/Qwen3.8-27B).
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+ It is not a standalone language model: it runs inside a speculative
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+ decoding server and drafts tokens for the target model to verify. The checkpoint is also
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+ mirrored at [`z-lab/Qwen3.8-27B-DFlash2`](https://huggingface.co/z-lab/Qwen3.8-27B-DFlash2).
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+
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+ DFlash 2 is a block-diffusion drafter for speculative decoding. It predicts
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+ a whole block of tokens in a single pass and keeps the top candidates at
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+ every position. A lightweight selector then traces one coherent path through them.
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+ Two-tap dynamic convolutions in the backbone keep the draft from decaying
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+ toward the end of the block. Decoding is lossless: greedy output
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+ matches the target model exactly, and sampling preserves its distribution.
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+
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+ <div align="center">
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+ <img src="assets/dflash2-figure.png" alt="DFlash 2: parallel block drafting with a candidate path selector" width="100%">
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+ </div>
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+
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+ ## Quick Start
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+
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+ Serve with [SGLang](https://github.com/sgl-project/sglang):
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+
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+ ```bash
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+ pip install "sglang[all] @ git+https://github.com/sgl-project/sglang.git#subdirectory=python"
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+
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+ python -m sglang.launch_server \
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+ --model-path Qwen/Qwen3.8-27B \
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+ --speculative-algorithm DFLASH \
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+ --speculative-draft-model-path incoai/Qwen3.8-27B-DFlash2 \
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+ --speculative-num-draft-tokens 8
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+ ```
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+
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+ Or with [vLLM](https://github.com/vllm-project/vllm):
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+
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+ ```bash
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+ pip install -U "vllm @ git+https://github.com/vllm-project/vllm.git@refs/pull/52816/head"
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+
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+ vllm serve Qwen/Qwen3.8-27B \
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+ --speculative-config '{
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+ "method": "dflash",
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+ "model": "incoai/Qwen3.8-27B-DFlash2",
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+ "num_speculative_tokens": 7
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+ }'
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+ ```
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+
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+ See the [blog post](https://inco.ai/blog/dflash2/) for other engines and more details.
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+
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+ ## Evaluation
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+
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+ - Runtime: SGLang on one NVIDIA H200, with FlashAttention 3 for target and draft attention
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+ - Speculation block size: 8 (7 draft tokens per verification step)
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+ - Sampling: Qwen3.8's officially recommended parameters (temperature 1.0, top-p 0.95, top-k 20), with `xhigh` reasoning effort
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+ - Maximum new tokens: 4096
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+ - Prompts: benchmark formatting from [`z-lab/dflash`](https://github.com/z-lab/dflash)
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+
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+ We compare autoregressive decoding, Qwen3.8's built-in seven-token MTP,
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+ a community DSpark drafter
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+ ([`RadixArk/Qwen3.8-27B-DSpark`](https://huggingface.co/RadixArk/Qwen3.8-27B-DSpark)),
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+ and DFlash 2. All speculative methods propose seven draft tokens per
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+ verification step.
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+
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+ ### Acceptance Length
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+
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+ Acceptance length is the per-request mean of completion tokens divided by verification steps.
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+ Higher is better.
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+
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+ | Task | MTP | DSpark | DFlash 2 |
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+ | :--- | ---: | ---: | ---: |
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+ | GSM8K | 5.02 | 4.36 | **5.46** |
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+ | MATH-500 | 4.72 | 3.92 | **5.28** |
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+ | HumanEval | 3.91 | 3.30 | **4.39** |
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+ | MBPP | 3.99 | 3.51 | **4.79** |
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+ | MT-Bench | 3.74 | 3.01 | **4.10** |
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+
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+ ### Throughput
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+
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+ Throughput is total output tokens divided by end-to-end wall time.
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+ Each cell shows `output tok/s (speedup vs. autoregressive)`.
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+
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+ #### Concurrency 1
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+
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+ | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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+ | :--- | ---: | ---: | ---: | ---: |
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+ | GSM8K | 68.9 | 178.5 (2.59×) | 185.3 (2.69×) | **236.1 (3.43×)** |
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+ | MATH-500 | 69.0 | 172.8 (2.51×) | 174.5 (2.53×) | **230.7 (3.34×)** |
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+ | HumanEval | 69.0 | 151.9 (2.20×) | 159.9 (2.32×) | **214.6 (3.11×)** |
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+ | MBPP | 69.0 | 153.1 (2.22×) | 163.3 (2.37×) | **226.9 (3.29×)** |
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+ | MT-Bench | 68.9 | 134.9 (1.96×) | 137.6 (2.00×) | **184.0 (2.67×)** |
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+
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+ #### Concurrency 8
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+
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+ | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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+ | :--- | ---: | ---: | ---: | ---: |
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+ | GSM8K | 467.2 | 1,022.1 (2.19×) | 1,040.8 (2.23×) | **1,328.7 (2.84×)** |
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+ | MATH-500 | 480.0 | 1,023.5 (2.13×) | 1,025.8 (2.14×) | **1,368.3 (2.85×)** |
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+ | HumanEval | 483.4 | 934.2 (1.93×) | 956.5 (1.98×) | **1,291.5 (2.67×)** |
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+ | MBPP | 478.0 | 938.1 (1.96×) | 974.1 (2.04×) | **1,328.0 (2.78×)** |
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+ | MT-Bench | 480.5 | 835.2 (1.74×) | 802.3 (1.67×) | **1,090.2 (2.27×)** |
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+
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+ #### Concurrency 32
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+
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+ | Task | Autoregressive | MTP | DSpark | DFlash 2 |
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+ | :--- | ---: | ---: | ---: | ---: |
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+ | GSM8K | 1,329.8 | 1,381.1 (1.04×) | 1,506.5 (1.13×) | **1,922.5 (1.45×)** |
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+ | MATH-500 | 1,505.8 | 1,415.6 (0.94×) | 1,429.0 (0.95×) | **1,951.8 (1.30×)** |
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+ | HumanEval | 1,546.5 | 1,296.8 (0.84×) | 1,330.1 (0.86×) | **1,799.0 (1.16×)** |
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+ | MBPP | 1,507.7 | 1,314.9 (0.87×) | 1,361.3 (0.90×) | **1,886.8 (1.25×)** |
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+ | MT-Bench | 1,507.4 | 1,159.7 (0.77×) | 1,115.5 (0.74×) | **1,525.3 (1.01×)** |
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+
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+ ## Citation
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+
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+ If you find DFlash 2 useful, please cite:
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+
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+ ```bibtex
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+ @misc{inco2026dflash2,
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+ title = {{DFlash 2: Keep Drafting Parallel}},
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+ author = {{Inco AI}},
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+ year = {2026},
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+ month = {August},
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+ url = {https://inco.ai/blog/dflash2/}
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+ }
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+ ```
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+
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+ Please also cite the original DFlash paper:
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+
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+ ```bibtex
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+ @inproceedings{chen2026dflash,
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+ title = {{DFlash: Block Diffusion for Flash Speculative Decoding}},
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+ author = {Chen, Jian and Liang, Yesheng and Liu, Zhijian},
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+ booktitle = {International Conference on Machine Learning (ICML)},
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+ year = {2026}
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+ }
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+ ```