Qwen3.6 27B Architect Polaris2 Fable B F451 — MTP ROCmFPX GGUF

Text-only ROCmFPX/ROCmFP4 GGUF builds of nightmedia/Qwen3.6-27B-Architect-Polaris2-Fable-B-F451, with the checkpoint's embedded one-layer MTP draft model preserved.

These are experimental AMD Strix Halo builds. The custom ROCmFPX tensor types require charlie12345/ROCmFPX; they will not load in an unmodified stock llama.cpp build.

Files

All three files retain 64 main transformer blocks plus the embedded blk.64 MTP block. The source checkpoint's vision tensors were intentionally omitted; these GGUFs are for text generation.

Checksums

179ec314e293cbce80620ecc5eeba75d8566d9d3fa1aab3169dffb524f530187  Qwen3.6-27B-Architect-Polaris2-Fable-B-F451-MTP-ROCmFP8.gguf
0acfe339d09a9f0864312eaac91ad3145cc30afc3ad9044c735c9224ae1b6fb4  Qwen3.6-27B-Architect-Polaris2-Fable-B-F451-MTP-iMatrix-ROCmFP4.gguf
2255f94eaa4bdb856b799eff7198a1d0e56ded53429c1c15523e8af441d9819a  Qwen3.6-27B-Architect-Polaris2-Fable-B-F451-MTP-iMatrix-ROCmFP8_QUALITY_Q6.gguf

Working ROCmFP8 router preset

This is the current text-only llama.cpp router preset used on a 128 GB Strix Halo system. It gives one slot the full native 262,144-token context, uses F16 KV, enables cross-turn checkpoint reuse, and runs the embedded MTP head with nmax=5.

The chat template is froggeric's chat_template.jinja v21.3. Download it separately and replace the example paths below.

[Qwen3.6-27B-Architect-Polaris2-Fable-B-F451-MTP-ROCmFP8]
model = /path/to/Qwen3.6-27B-Architect-Polaris2-Fable-B-F451-MTP-ROCmFP8.gguf
chat-template-file = /path/to/chat_template.jinja
chat-template-kwargs = {"preserve_thinking": true}
ctx-size = 262144
parallel = 1
flash-attn = on
batch-size = 2048
ubatch-size = 256
threads = 16
threads-batch = 16
cache-type-k = f16
cache-type-v = f16
checkpoint-every-n-tokens = 256
cache-reuse = 256
cache-ram = 65536
mmap = 0
metrics = 1
spec-type = draft-mtp
spec-draft-device = Vulkan0
spec-draft-ngl = all
spec-draft-n-max = 5
spec-draft-p-min = 0.0
spec-draft-p-split = 0.10
reasoning = on
reasoning-format = deepseek
temp = 0.6
top-p = 0.95
top-k = 20
min-p = 0.0
repeat-penalty = 1.0

cache-ram = 65536 and F16 KV are intentionally memory-hungry settings for a 128 GB unified-memory machine. Reduce the reuse-cache ceiling and/or use Q8 KV on smaller systems. Temperature 0.6 is the precise/coding profile; 1.0 is a useful starting point for general or creative work.

Validation notes

• Native 262,144-token context allocation passed for every artifact with both Q8/Q8 and F16/F16 KV.
• ROCmFP8 passed a deterministic 131,072-token planted-fact recall probe, 4/4 facts recovered.
• ROCmFP8 measured 12–14 tok/s in the original controlled MTP tests. With the router profile above, a short routed smoke measured 21.9 tok/s and a 4.46-token mean accepted MTP draft length.
• ROCmFP4 measured approximately 21–23 tok/s in short MTP tests on this host.
• These are directional single-host measurements, not benchmark medians.

Host: AMD Strix Halo / RADV GFX1151, 128 GB unified memory. Runtime: ROCmFPX commit 61f2f2d7bc4955e9bca821095ef69125837133b5 (llama.cpp build 162). The build checkout also contained a pre-existing MoE-only local diff (1783321e5a89eadc541ce2905874e5ed1172223204f257b5e569278c4f34004f); this dense 27B model has no expert tensors affected by that code path.

Build summary

• Source revision: nightmedia/Qwen3.6-27B-Architect-Polaris2-Fable-B-F451@d92178a
• One checked BF16 text+MTP GGUF was converted from the pinned source.
• ROCmFP8 was quantized directly from BF16 without an imatrix.
• ROCmFP4 and ROCmFP8_QUALITY_Q6 use the same narrative/general importance matrix: 511 × 2,048-token chunks, 496/496 quantizable tensor coverage. The calibration corpus used public-domain Project Gutenberg texts with whole-document holdouts.

Upstream and attribution

• Source merge and model work: NightMedia — Qwen3.6-27B Architect Polaris2 Fable B F451
• Base architecture: Qwen — Qwen3.6-27B
• Custom quantization/runtime: charlie12345/ROCmFPX
• Upstream llama.cpp: ggml-org/llama.cpp
• Runtime and ROCmFP4 recipe reference: Plunderstruck — Qwen3.6-27B MTP ROCmFP4 GGUF
• Qwen3.6 chat template: froggeric/Qwen-Fixed-Chat-Templates
• Public-domain calibration texts: Project Gutenberg

The model weights and this derivative packaging retain the upstream Apache-2.0 license. Please consult the linked source model card for its full merge lineage and intended-use notes.