File	Purpose	Size	SHA-256
`Qwen3.8-27B-heretic-ara-MXFP6-MXFP8.gguf`	27B target	20.72 GiB	`238141420ea8f5e8f051dd5c42b741ad09d02565f540aba5ac233dff7f0490c1`
`Qwen3.8-27B-DFlash2-MXFP6_E2M3.gguf`	DFlash2 companion draft	1.47 GiB	`590f4b562f23019f28871bad8c925d6932ccde79c88e27c3228e7d9159859620`

The target has 27,320,697,856 parameters and is approximately 6.51 BPW. Its matrix tensor mix is:

396 MXFP6_E2M3 tensors;
110 OCP MXFP8 tensors;
MTP tensors preserved.

MXFP6_E2M3 is an experimental GGUF extension and is not compatible with stock llama.cpp. Use the linked fork.

Sources

Target source: heretic-org/Qwen3.8-27B-heretic-ara
Base model: Qwen/Qwen3.8-27B
Draft source: incoai/Qwen3.8-27B-DFlash2
Quantization/runtime source: sirus20x6/llama.cpp-blackwell-dflash2
Advanced quantizer: michaelw9999/advanced-gguf-quantizer

Download and run

bash

git clone https://github.com/sirus20x6/llama.cpp-blackwell-dflash2
cd llama.cpp-blackwell-dflash2
./build-blackwell-dflash2.sh

hf download \
  sirus/Qwen3.8-27B-heretic-ara-MXFP6-MXFP8-DFlash2-GGUF \
  Qwen3.8-27B-heretic-ara-MXFP6-MXFP8.gguf \
  Qwen3.8-27B-DFlash2-MXFP6_E2M3.gguf \
  --local-dir models

./run-qwen3.8-heretic-dflash2.sh

The launcher defaults to one 262144-token slot, MXFP8 K/V cache, and seven DFlash2 draft tokens. The checkpoint's trained block size is eight, including one anchor token.

Performance note

The earlier tri-quant target was slower in our observed testing. A previous version of this card included throughput figures collected with differing runtime, cache, context, and execution settings. Those values were not a valid controlled comparison and have been withdrawn. No comparative performance claim is made here until the artifacts are rerun under an identical benchmark configuration.

Validation and limitations

Structural GGUF inspection passed.
MTP preservation passed.
Completion smoke tests passed.
Device-resident DFlash2 handoff was tested through a 65,588-token request.
No final PPL/KLD evaluation was produced, so this release makes no quantified quality claim against BF16.
The target artifact is text-only.
MXFP6_E2M3 and the bundled runtime are experimental.

License and attribution

The source target and DFlash2 draft are Apache-2.0. See LICENSE.

The runtime repository retains llama.cpp, advanced-gguf-quantizer, TurboQuant, and Four Over Six notices and links. DFlash2 originates from Inco AI. The Heretic ARA model originates from heretic-org and the Heretic project.