Mirror Qwen3.8-27B-DFlash2 (z-lab) with provenance header; Apache-2.0

.gitattributes

@@ -33,3 +33,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.zip filter=lfs diff=lfs merge=lfs -text
 *.zst filter=lfs diff=lfs merge=lfs -text
 *tfevents* filter=lfs diff=lfs merge=lfs -text
+assets/dflash2-figure.png filter=lfs diff=lfs merge=lfs -text

LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright 2026 Alibaba Cloud
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

README.md

@@ -0,0 +1,167 @@
+---
+license: apache-2.0
+library_name: transformers
+pipeline_tag: text-generation
+base_model:
+  - Qwen/Qwen3.8-27B
+inference: false
+tags:
+  - dflash2
+  - speculative-decoding
+  - block-diffusion
+  - draft-model
+  - sglang
+  - vllm
+  - mirror
+  - veloGB10
+---
+
+# Qwen3.8-27B-DFlash2 (mirror)
+
+> **This repository is a mirror of [z-lab/Qwen3.8-27B-DFlash2](https://huggingface.co/z-lab/Qwen3.8-27B-DFlash2).**
+> We mirror it here so it can be pulled from a stable location. The model, weights, and the
+> original model card below are **unmodified** from the upstream source — full credit to **z-lab / Inco AI**.
+> This mirror is provided for the [veloGB10](https://github.com/sf-stav/veloGB10) engine and workflow.
+>
+> **License: Apache-2.0** (the upstream card declares `apache-2.0`; a copy of the license is
+> included in this repository as `LICENSE`). The upstream [README](https://huggingface.co/z-lab/Qwen3.8-27B-DFlash2/raw/main/README.md)
+> is reproduced in full below.
+
+---
+
+# Qwen3.8-27B-DFlash2
+
+[Blog](https://inco.ai/blog/dflash2/) | [GitHub](https://github.com/z-lab/dflash)
+
+This repository contains the DFlash 2 draft model for
+[`Qwen/Qwen3.8-27B`](https://huggingface.co/Qwen/Qwen3.8-27B).
+It is not a standalone language model: it runs inside a speculative
+decoding server and drafts tokens for the target model to verify. The checkpoint is also
+mirrored at [`z-lab/Qwen3.8-27B-DFlash2`](https://huggingface.co/z-lab/Qwen3.8-27B-DFlash2).
+
+DFlash 2 is a block-diffusion drafter for speculative decoding. It predicts
+a whole block of tokens in a single pass and keeps the top candidates at
+every position. A lightweight selector then traces one coherent path through them.
+Two-tap dynamic convolutions in the backbone keep the draft from decaying
+toward the end of the block. Decoding is lossless: greedy output
+matches the target model exactly, and sampling preserves its distribution.
+
+<div align="center">
+  <img src="assets/dflash2-figure.png" alt="DFlash 2: parallel block drafting with a candidate path selector" width="100%">
+</div>
+
+## Quick Start
+
+Serve with [SGLang](https://github.com/sgl-project/sglang):
+
+```bash
+pip install "sglang[all] @ git+https://github.com/sgl-project/sglang.git#subdirectory=python"
+
+python -m sglang.launch_server \
+  --model-path Qwen/Qwen3.8-27B \
+  --speculative-algorithm DFLASH \
+  --speculative-draft-model-path incoai/Qwen3.8-27B-DFlash2 \
+  --speculative-num-draft-tokens 8
+```
+
+Or with [vLLM](https://github.com/vllm-project/vllm):
+
+```bash
+pip install -U "vllm @ git+https://github.com/vllm-project/vllm.git@refs/pull/52816/head"
+
+vllm serve Qwen/Qwen3.8-27B \
+  --speculative-config '{
+    "method": "dflash",
+    "model": "incoai/Qwen3.8-27B-DFlash2",
+    "num_speculative_tokens": 7
+  }'
+```
+
+See the [blog post](https://inco.ai/blog/dflash2/) for other engines and more details.
+
+## Evaluation
+
+- Runtime: SGLang on one NVIDIA H200, with FlashAttention 3 for target and draft attention
+- Speculation block size: 8 (7 draft tokens per verification step)
+- Sampling: Qwen3.8's officially recommended parameters (temperature 1.0, top-p 0.95, top-k 20), with `xhigh` reasoning effort
+- Maximum new tokens: 4096
+- Prompts: benchmark formatting from [`z-lab/dflash`](https://github.com/z-lab/dflash)
+
+We compare autoregressive decoding, Qwen3.8's built-in seven-token MTP,
+a community DSpark drafter
+([`RadixArk/Qwen3.8-27B-DSpark`](https://huggingface.co/RadixArk/Qwen3.8-27B-DSpark)),
+and DFlash 2. All speculative methods propose seven draft tokens per
+verification step.
+
+### Acceptance Length
+
+Acceptance length is the per-request mean of completion tokens divided by verification steps.
+Higher is better.
+
+| Task | MTP | DSpark | DFlash 2 |
+| :--- | ---: | ---: | ---: |
+| GSM8K | 5.02 | 4.36 | **5.46** |
+| MATH-500 | 4.72 | 3.92 | **5.28** |
+| HumanEval | 3.91 | 3.30 | **4.39** |
+| MBPP | 3.99 | 3.51 | **4.79** |
+| MT-Bench | 3.74 | 3.01 | **4.10** |
+
+### Throughput
+
+Throughput is total output tokens divided by end-to-end wall time.
+Each cell shows `output tok/s (speedup vs. autoregressive)`.
+
+#### Concurrency 1
+
+| Task | Autoregressive | MTP | DSpark | DFlash 2 |
+| :--- | ---: | ---: | ---: | ---: |
+| GSM8K | 68.9 | 178.5 (2.59×) | 185.3 (2.69×) | **236.1 (3.43×)** |
+| MATH-500 | 69.0 | 172.8 (2.51×) | 174.5 (2.53×) | **230.7 (3.34×)** |
+| HumanEval | 69.0 | 151.9 (2.20×) | 159.9 (2.32×) | **214.6 (3.11×)** |
+| MBPP | 69.0 | 153.1 (2.22×) | 163.3 (2.37×) | **226.9 (3.29×)** |
+| MT-Bench | 68.9 | 134.9 (1.96×) | 137.6 (2.00×) | **184.0 (2.67×)** |
+
+#### Concurrency 8
+
+| Task | Autoregressive | MTP | DSpark | DFlash 2 |
+| :--- | ---: | ---: | ---: | ---: |
+| GSM8K | 467.2 | 1,022.1 (2.19×) | 1,040.8 (2.23×) | **1,328.7 (2.84×)** |
+| MATH-500 | 480.0 | 1,023.5 (2.13×) | 1,025.8 (2.14×) | **1,368.3 (2.85×)** |
+| HumanEval | 483.4 | 934.2 (1.93×) | 956.5 (1.98×) | **1,291.5 (2.67×)** |
+| MBPP | 478.0 | 938.1 (1.96×) | 974.1 (2.04×) | **1,328.0 (2.78×)** |
+| MT-Bench | 480.5 | 835.2 (1.74×) | 802.3 (1.67×) | **1,090.2 (2.27×)** |
+
+#### Concurrency 32
+
+| Task | Autoregressive | MTP | DSpark | DFlash 2 |
+| :--- | ---: | ---: | ---: | ---: |
+| GSM8K | 1,329.8 | 1,381.1 (1.04×) | 1,506.5 (1.13×) | **1,922.5 (1.45×)** |
+| MATH-500 | 1,505.8 | 1,415.6 (0.94×) | 1,429.0 (0.95×) | **1,951.8 (1.30×)** |
+| HumanEval | 1,546.5 | 1,296.8 (0.84×) | 1,330.1 (0.86×) | **1,799.0 (1.16×)** |
+| MBPP | 1,507.7 | 1,314.9 (0.87×) | 1,361.3 (0.90×) | **1,886.8 (1.25×)** |
+| MT-Bench | 1,507.4 | 1,159.7 (0.77×) | 1,115.5 (0.74×) | **1,525.3 (1.01×)** |
+
+## Citation
+
+If you find DFlash 2 useful, please cite:
+
+```bibtex
+@misc{inco2026dflash2,
+  title  = {{DFlash 2: Keep Drafting Parallel}},
+  author = {{Inco AI}},
+  year   = {2026},
+  month  = {August},
+  url    = {https://inco.ai/blog/dflash2/}
+}
+```
+
+Please also cite the original DFlash paper:
+
+```bibtex
+@inproceedings{chen2026dflash,
+  title     = {{DFlash: Block Diffusion for Flash Speculative Decoding}},
+  author    = {Chen, Jian and Liang, Yesheng and Liu, Zhijian},
+  booktitle = {International Conference on Machine Learning (ICML)},
+  year      = {2026}
+}
+```

config.json

@@ -0,0 +1,57 @@
+{
+  "architectures": [
+    "DFlash2DraftModel"
+  ],
+  "attention_bias": false,
+  "attention_dropout": 0.0,
+  "bos_token_id": null,
+  "is_causal": false,
+  "dflash_config": {
+    "block_size": 8,
+    "conv_group_size": 16,
+    "conv_kernel_size": 2,
+    "mask_token_id": 248070,
+    "selector_rank": 256,
+    "selector_top_k": 16,
+    "target_layer_ids": [
+      5,
+      19,
+      33,
+      47,
+      61
+    ]
+  },
+  "dtype": "bfloat16",
+  "eos_token_id": 248044,
+  "head_dim": 128,
+  "hidden_act": "silu",
+  "hidden_size": 5120,
+  "initializer_range": 0.02,
+  "intermediate_size": 17408,
+  "layer_types": [
+    "sliding_attention",
+    "sliding_attention",
+    "sliding_attention",
+    "sliding_attention",
+    "sliding_attention"
+  ],
+  "max_position_embeddings": 262144,
+  "max_window_layers": 5,
+  "model_type": "qwen3",
+  "num_attention_heads": 32,
+  "num_hidden_layers": 5,
+  "num_key_value_heads": 8,
+  "num_target_layers": 64,
+  "pad_token_id": 248044,
+  "rms_norm_eps": 1e-06,
+  "rope_parameters": {
+    "rope_theta": 10000000,
+    "rope_type": "default"
+  },
+  "sliding_window": 2048,
+  "tie_word_embeddings": false,
+  "transformers_version": "5.15.0",
+  "use_cache": true,
+  "use_sliding_window": true,
+  "vocab_size": 248320
+}

model.safetensors

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:67fc76d68dc5a9415511a4f394ef744d67510cd20e93b37cc2cc7d28e4bab65c
+size 3848817896