Qwen3.8-27B Q6 on one Arc Pro B70: what each software change did
Reported by Reddit user on r/LocalLLaMA (summarized by @wei_wang on X)| Model & revision | Qwen3.8-27B; exact GGUF file and revision Unknown |
|---|---|
| Quant | Q6 (exact file Unknown) |
| Runtime & version | Steps 1–3: Ollama on Vulkan (Mesa 25.2, then Mesa 26.2). Steps 4–5: llama.cpp llama-server built with SYCL (Intel oneAPI); llama.cpp version Unknown |
| Topology | 1x Intel Arc Pro B70 (32 GB); kernel 6.17 or newer (Ubuntu 7.0 HWE kernel), Resizable BAR on, Intel compute runtime from a PPA |
| Input / output / context | Figures from the author's 16k-context column; output length Unknown |
| Concurrency | Unknown |
| Speculative decoding | Off in steps 1–4. On only in step 5: MTP with up to 4 draft tokens (--spec-type draft-mtp --spec-draft-n-max 4) |
| How speed was timed | Unknown |
| Date measured | Unknown (summary posted 2026-11-10) |
| Source | Original Reddit post (r/LocalLLaMA) · @wei_wang on X, 2026-11-10 |
| Evidence status | Self-reported, not independently reproduced |
Plain decoding (no drafting), generation at 16k context
| What | Reported | Note |
|---|---|---|
| 1. Ollama + Mesa 25.2 | 6.8 tok/s | — |
| 2. Mesa 26.2 | 19.4 tok/s | — |
| 3. Mesa 26.2, f16 KV cache | 33 tok/s | — |
| 4. llama.cpp SYCL, f16 KV cache | 49 tok/s | — |
With speculative decoding (MTP, up to 4 drafts)
| What | Reported | Note |
|---|---|---|
| 5. llama.cpp SYCL, q8_0 KV cache, MTP | 56.5 tok/s | — |
This page's own figure for Qwen3.8-27B is an estimate for Q4_K_M and is unchanged. This ladder used Q6 and different engines, so it isn't a check of that estimate.
The author found that on Vulkan any quantized KV cache slowed generation a lot, so steps 2–3 keep f16 there. Ollama has no SYCL backend.
Caveats
- One person's setup on one card.
- Self-reported, not independently reproduced.
- Step 5 uses drafting; compare steps 1–4 with each other, not with step 5.