Qwen3.5-9B "thinking" slows local chat

Qwen3.5-9B's reasoning-first approach marks a paradigm shift from raw inference speed to verified logical depth, though it introduces a friction point for users accustomed to the near-instant response of traditional local LLMs.

• –The model’s "Thinking" mode generates explicit reasoning tokens before the final output, which is a deliberate feature for logic but a bottleneck for simple chat.
• –RTX 4060 (8GB) users often trigger "VRAM spill" into system RAM when using Q8 or higher quantizations, resulting in extreme slowness that masks the model's actual performance.
• –Qwen3.5-9B includes a "Thinking Budget" and "Fast Mode" to bypass or cap reasoning tokens, a critical configuration for developers building low-latency agents.
• –The hybrid Gated DeltaNet architecture enables impressive intelligence density, proving that 9B parameters can compete with frontier models if given the compute time to "reason."