MTP benchmark results: the nature of the generative task dictates whether you will benefit (coding) or get slower inference (creative) from speculative inference. No other factor comes close.

I recently published MTP quants of Qwen 3.6 27B and I was suprised by the reports here on reddit, and on HF, of users who were experiencing worst speed with speculative inference than without. This did not match what I was seeing, but when I tried to reproduce their exact usage, it confirmed what they were experiencing. I tried to analyse the problem, made a few conjectures which later turned out to be false, and started a full blown systematical analysis, running 300+ tests and benchmarks, collecting and comparing the results of changing various parameters.