Qwen3.5 9B

User reports Qwen3.5-9B running at about 25 tok/s without speculation and 33-37 tok/s with MTP speculative decoding on a fanless MacBook Air M5 16GB. Setup is a custom MLX engine (QVex-3.5) with a self-made qvex-q4 4-bit imatrix quant, using Qwen's own MTP head as the draft model (about 490 MB). The custom quant is 2.7x closer to bf16 than stock MLX 4-bit (KL 0.026 vs 0.069). A 3-bit build was about 13% faster but used 20-45% more energy per token, and MTP costs 10-25% more energy per token. With a 512-token thinking budget the model solved 24/24 tasks; the user calls this a sanity check rather than a benchmark, tested on one machine only.