Qwen3.6 35B (3B active)

User reports Qwen3.6-35B-A3B at 20.7 t/s at 127k context on an Intel Arc Pro B70 32GB, down from 70.7 t/s at depth 0. Setup is llama.cpp b10235 (Vulkan) with Q4_K_M, -ngl 999 -ub 512 -fa 0, single card in a PCIe-passthrough VM with 6 vCPU and 16 GB RAM. The user attributes the depth collapse to a memory-latency-bound decode attention kernel, measuring a constant ~21-25 ns per KV position per full-attention layer across backends, models and quants; vLLM XPU on the same card stays flat to 127k. Also reports a silent CPU fallback for prefill score tensors, a SYCL ~16.5 GiB weight-buffer limit, and a ~19% MoE decode regression from b8183 to b10235.