Add speculative decoding via EasiiX/Qwen3.8-Flash-Next-MTP-Strix-Halo-GGUF Q8_0 sidecar (4.1 GB, qwen4exp architecture matching the main model). - serve-frank-large.sh: SPEC_ARGS array, draft model existence check, spec defaults (n_max 4, p_min 0.75, ngl 999, ROCm0) - frank-default-large.env: MTP tunables section, fix 'no MTP' comment - kingjones-strix-rocmfp4.md: MTP Draft Head section, spec flags in serving profile, EasiiX + PR #27739 citations Set SPEC_TYPE=none in the env to disable speculative decoding.
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type, title, description, tags, timestamp
| type | title | description | tags | timestamp | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| reference | kingjones Qwen3.8-Flash-Next ROCmFP4 STRIX on Dankclaw | kingjones777/Qwen3.8-Flash-Next-ROCmFP4-STRIX-GGUF served by the ROCmFPX llama.cpp fork. 177B params (56B MoE + 51.2B PLE), single 113.47 GiB GGUF. frank-default-large. |
|
2026-08-27 |
kingjones Qwen3.8-Flash-Next ROCmFP4 STRIX on Dankclaw
Active since 2026-08-27. Replaced the STRIX_LEAN deployment on the same build. Same GPU memory profile, larger PLE table.
frank-default-large (port 7770) serves
Qwen3.8-Flash-Next-Q4_0-ROCmFP4-STRIX from kingjones777 on Hugging Face.
A single GGUF file, 113.47 GiB. Text-only (no mmproj). MTP draft head
loaded as a separate GGUF sidecar (see MTP Draft Head below).
Model Architecture
Base model: Qwen3.8-Flash-Next (177B parameters total).
| Component | Params | Details |
|---|---|---|
| MoE experts | 125.8B | 512 experts, 10 used per token |
| Attention | dense | 48 layers (12 attn + 36 SSM) |
| PLE table | 51.2B | per_layer_token_embd, Q8_0 |
| lm head | ~0.3% | Q6_K |
The PLE (per-layer embedding) n-gram table is the only thing that differs between STRIX, STRIX_LEAN, and FAST tiers. Everything else is byte-identical.
File Details
| Field | Value |
|---|---|
| File | Qwen3.8-Flash-Next-Q4_0-ROCmFP4-STRIX.gguf |
| Size | 113.47 GiB |
| Format | Single GGUF (not sharded) |
| file_type | 105 (Q4_0_ROCMFP4_STRIX) |
| General | 113.47 GiB, 5.51 bpw |
Tensor composition:
| Tensor group | Type |
|---|---|
MoE expert weights (ffn_*_exps, 144) |
TYPE_101 (ROCmFP4, 4.251 bpw) |
Shared expert (ffn_*_shexp, 144) |
TYPE_101 |
Attention (attn_*, 120) |
half TYPE_100, half TYPE_101 |
PLE (per_layer_token_embd.weight) |
Q8_0 — 50.66 GiB |
token_embd.weight |
Q6_K |
output.weight (lm head) |
Q6_K |
| Norms / biases | F32 |
File Type Reference
| Tier | file_type | PLE table | Total size |
|---|---|---|---|
| FAST | TYPE_106 | 25.34 GiB | 87.94 GiB |
| STRIX_LEAN | TYPE_105 (old STRIX_LEAN) | 35.76 GiB | 98.49 GiB |
| STRIX | 105 (Q4_0_ROCMFP4_STRIX) |
50.66 GiB | 113.47 GiB |
TYPE_100 = 4.506 bpw, TYPE_101 = 4.251 bpw (measured exactly by solving three files for two unknowns).
Memory
The PLE table never enters GPU VRAM. It streams from the file through the OS page cache.
| Context | GTT at load | GTT after prompt | GPU resident |
|---|---|---|---|
| 8,192 | 63.3 GiB | 63.6 GiB | ~63 GiB |
| 32,768 | 64.1 GiB | 64.8 GiB | |
| 65,536 | 65.1 GiB | 66.2 GiB | |
| 131,072 | 67.2 GiB | 69.1 GiB | ~69 GiB |
~63 GiB is the non-PLE mass plus compute buffers. The PLE table does not grow GPU memory regardless of context depth.
Three critical consequences:
--no-mmapgets you OOM-killed. It forces the PLE into anonymous memory (neither file-backed nor reclaimable). The cgroup killer takes the process with nothing in the server log — onlydmesgshows the evidence.- Don't force PLE to CPU with
-ot. Measured generation dropped from ~23 to 13.4 tok/s. The kernel streams it better than any offload hack. - A bigger tier costs disk, not GPU memory. If you have storage, take STRIX.
Performance
Measured on Ryzen AI MAX+ 395 (gfx1151, ROCm 7.2.4), 49/49 offload. Prompts sized to 85% of context window:
| Context | Prompt tokens | pp tok/s | gen tok/s |
|---|---|---|---|
| 8,192 | 6,963 | 279 | 22.02 |
| 32,768 | 27,852 | 264 | 20.52 |
| 65,536 | 55,705 | 234 | 18.23 |
| 131,072 | 111,411 | 185 | 15.34 |
Short prompts (~3,300 tokens): 381 tok/s prompt processing, 22.7 tok/s generation (median of 3 runs).
Benchmark: threads-batch tuning
Sweeped --threads-batch (16, 32, 48, 64, 80, 96, 128) with a 64K-token
prompt via HTTP API (max_tokens=1). Fresh server start per value.
| threads-batch | prefill tok/s | wall time |
|---|---|---|
| 16 | 373.5 | 62.9s |
| 32 | 354.4 | 66.3s |
| 48 | 344.1 | 68.3s |
| 64 | 344.7 | 68.2s |
| 80 | 344.4 | 68.2s |
| 96 | 357.1 | 65.8s |
| 128 | 321.1 | 73.2s |
Optimal: --threads-batch 16 (373.5 tok/s). Lower thread batching wins
for prefill on this model -- fewer threads compete for GPU resources during
the prompt processing phase. The default of 32 is 5.1% slower. Above 64,
performance plateaus then declines (128 is 14% worse than optimal).
Benchmark: decode throughput
Sweeped --threads-batch (8, 16, 32) with a ~23.5K-token code prompt and
256 generated tokens via HTTP API. Fresh server start per value.
| threads-batch | gen tokens | wall time | gen tok/s |
|---|---|---|---|
| 16 | 256 | 74.8s | 3.4 |
| 32 | 256 | 75.0s | 3.4 |
| 8 | 256 | 76.6s | 3.3 |
Decode throughput is essentially flat across all tested values. TB=16 and
TB=32 are identical at 3.4 tok/s; TB=8 is marginally slower at 3.3 tok/s.
Combined with the 5.1% prefill advantage at lower thread counts, --threads-batch 16 is the optimal setting for both phases.
Serving Profile
Runtime: charlie12345/ROCmFPX llama-server built at
/home/dank/GitPackages/ROCmFPX/build-qwen38.
Required flags:
llama-server \
--model Qwen3.8-Flash-Next-Q4_0-ROCmFP4-STRIX.gguf \
--host 0.0.0.0 --port 7770 --jinja \
--device ROCm0 --gpu-layers 999 \
--fit off --flash-attn on \
--ctx-size 524288 --parallel 2 \
--batch-size 4096 --ubatch-size 4096 \
--cache-type-k f16 --cache-type-v f16 \
--threads 16 --threads-batch 16 \
--ctx-checkpoints 16 --cache-ram 8192 \
--cache-prompt --cache-idle-slots --metrics \
--temp 0.7 --top-p 0.8 --top-k 20 --min-p 0.0 \
--presence-penalty 1.5 \
--reasoning on --reasoning-format deepseek --reasoning-budget -1 \
--chat-template-file chat-template.jinja \
--chat-template-kwargs '{"enable_thinking":true,"preserve_thinking":true,"preserve_reasoning":true}' \
--spec-type draft-mtp,ngram-mod \
--model-draft mtp-Qwen3.8-Flash-Next-Q8_0.gguf \
--spec-draft-n-max 4 --spec-draft-p-min 0.75 \
--spec-draft-ngl 999 --spec-draft-device ROCm0 \
--spec-draft-type-k f16 --spec-draft-type-v f16
Key choices:
--fit off— auto-fit code segfaults on this model's qwen4exp hyper-connection/indexer configuration.- mmap (default) — do NOT use
--no-mmap. See memory section. --gpu-layers 999— all layers on SVM-backed GPU pool.--ctx-size 524288— above model's max (131072); llama.cpp clamps internally.--spec-type draft-mtp,ngram-mod— MTP draft head + ngram-mod fallback. Thengram-modcombo is recommended by the HF card; the prior dense 27B measurement showed ngram under MTP hurt by 4-5 t/s (kingjones-strix-mtp). Benchmark both before committing.--spec-draft-p-min 0.75— confidence gate. Without it, low-acceptance prose loses more to rejected drafts than it gains (per the HF card).
MTP Draft Head
The MTP (multi-token-prediction) draft head from
EasiiX/Qwen3.8-Flash-Next-MTP-Strix-Halo-GGUF
(Q8_0, 4.1 GB). Architecture qwen4exp, matching the main model. Loaded
as a separate GGUF sidecar via --model-draft.
| Field | Value |
|---|---|
| File | mtp-Qwen3.8-Flash-Next-Q8_0.gguf |
| Size | 4.1 GB (4,137,429,088 B) |
| Quant | Q8_0 |
| Architecture | qwen4exp |
| Source | EasiiX/Qwen3.8-Flash-Next-MTP-Strix-Halo-GGUF |
Measured (HF card, gfx1151, UD-IQ3_XXS target, temp 0): decode +50% on
code (23.5 → 35.7 t/s, ~85% acceptance), +49% at 156K context depth.
Speculative decoding is lossless at temp 0. Our service runs at temp 0.7,
so expect lower acceptance; the p_min 0.75 gate compensates.
Caveats:
- The MTP head is from the original
Qwen/Qwen3.8-Flash-Next; our model is the "Uncensored" (abliterated) variant. Abliteration modifies a small number of weight vectors, not the full model — acceptance may be marginally lower. - The HF card's tested fork is
Aristo94/EngramHalo.cpp, not ourcharlie12345/ROCmFPX. Both have PRs #27739 (MTP) + #27742 (qwen4exp) merged, so the MTP mechanism is the same upstream code. If the draft load crashes, check for Strix-Halo kernel patch differences first. - Set
SPEC_TYPE=noneinscripts/frank-default-large.envto disable.
Deployment
Download
# on Dankclaw
TOKEN=$(cat ~/.cache/huggingface/token)
DIR=/home/dank/models/kingjones-Qwen3.8-Flash-Next-ROCmFP4-STRIX
mkdir -p "$DIR"
curl -fsSL -C - -o "$DIR/Qwen3.8-Flash-Next-Q4_0-ROCmFP4-STRIX.gguf" \
--retry 5 --retry-delay 3 --retry-max-time 7200 \
-H "Authorization: Bearer $TOKEN" \
"https://huggingface.co/kingjones777/Qwen3.8-Flash-Next-ROCmFP4-STRIX-GGUF/resolve/main/Qwen3.8-Flash-Next-Q4_0-ROCmFP4-STRIX.gguf"
The file is 113.47 GiB. Allow ~20-30 minutes for download depending on network.
Swap procedure
- Stop service:
sudo systemctl stop frank-default-large - Remove old model dir:
rm -rf /home/dank/models/kingjones-Qwen3.8-Flash-Next-ROCmFP4-STRIX_LEAN - Start service:
sudo systemctl start frank-default-large - Verify health:
curl http://192.168.0.143:7770/health
Config files
- Env:
scripts/frank-default-large.env - Serve:
scripts/serve-frank-large.sh - Chat template:
scripts/chat-template.jinja
Known Issues
- Patched llama.cpp required. PR #27742 merged into the ROCmFPX fork. Stock builds reject these files (TYPE_100/101 have no number in stock ggml).
- Single-file payload. Not sharded. Use
hf downloador a resumable curl. Browser download unreliable for 113 GiB. - Model load is slow. A few minutes cold for the 113 GiB file with a
fresh KV cache. Health returns 503 while loading. Do not kill the process.
deploy.shwaits up to 20 minutes. - Kernel spam about
amdgpu: SVM mapping failedis a known documented symptom, not root cause. Investigate other causes before assuming memory pressure.
Citations
- kingjones777/Qwen3.8-Flash-Next-ROCmFP4-STRIX-GGUF
- Qwen/Qwen3.8-Flash-Next base model
- charlie12345/ROCmFPX — fork with PR #27742 (qwen4exp architecture)
- EasiiX/Qwen3.8-Flash-Next-MTP-Strix-Halo-GGUF — MTP draft head sidecar
- llama.cpp PR #27739 — MTP draft head support