claude-botandClaude Opus 5
7658cf8bb6
Measured, same model, same documents, only the quantisation differs:
Qwen3.6-35B-A3B Q4_K_M ~21 GB 11.0 tok/s
Qwen3.6-35B-A3B Q8_0 ~34 GB 10.3 tok/s
I predicted ~6 tok/s for Q8 — a halving, on the reasoning that doubling bytes
per active parameter doubles what crosses the memory bus. It cost ten percent.
So decode is not bandwidth-bound for this MoE at all. It is compute-bound on
many small per-expert matmuls, which retroactively explains a measurement I
recorded but never followed through: the MoE reached 21.4 GB/s against a
53.9 GB/s ceiling. It was already leaving 60% of the bus idle, so more bytes
cost almost nothing.
That formula has been steering decisions in this file — it is what ranked
candidates by size and what I used to predict runtimes. It predicts dense
models and not this one.
Practical consequence: higher precision is nearly free on an MoE here.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>