[abrahamzewoudie]

This applies on top of vllm-project#61573. An MTP verify step is wider than a plain decode, so the mono graph turned off. K1 stays on vLLM's GDN core, which can roll a rejected draft back. K2 stays on the fused MXFP4 feed-forward while the step fits the K2 cap. Quark MXFP4 checkpoints store mtp.* as BF16 under quantization_config.exclude, so those draft weights load unquantized.

Serve with speculative-config: {"method": "mtp", "num_speculative_tokens": 3} and VLLM_ROCM_MONO_DECODE=1. k=3 is the best combined geomean at TP1 and TP2. VL is highest at k=2.

MI355X, 20-config sweep per TP, versus the best Argos mono kernel with no speculative decoding. The k=1 column is from the earlier k=1 summary.

TP1. Mono kernel + MTP vs mono kernel

	k=1	k=2	k=3	k=4
TP1 text, Mono+MTP over Mono	+6.5%	+11.3%	+13.4%	+10.9%
TP1 VL, Mono+MTP over Mono	+4.5%	+8.6%	+8.0%	+6.0%
TP1 combined, Mono+MTP over Mono	+5.7%	+10.2%	+11.2%	+8.9%

TP2. Mono kernel + MTP vs mono kernel

	k=1	k=2	k=3	k=4
TP2 text, Mono+MTP over Mono	+5.0%	+10.6%	+12.3%	+9.5%
TP2 VL, Mono+MTP over Mono	−0.7%	+4.5%	+3.3%	+1.5%
TP2 combined, Mono+MTP over Mono	+2.7%	+8.1%	+8.6%	+6.2%

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[abrahamzewoudie]

Closing this fork pull request. The same branch is open on vllm-project/vllm as vllm-project#64720.