'Loaded fine' and 'runs fast' are different claims. Every NVFP4 load now
prints a diagnostics block that settles which one you have:
- comfy_kitchen backend census (the big one: torch built for CUDA < 13
disables ck's CUDA backend, so quantized matmuls silently fall through
to the pure-PyTorch eager backend - correct output, ZERO speedup, with
an explicit warning line when detected)
- torch/cuda build + device capability
- loaded-model layer census: nvfp4 layers vs layers flagged
full-precision emulation (pre-Blackwell GPUs)
- a timed 4096x4096 GEMM probe (incl. dynamic input quantization):
bf16 vs nvfp4 wall time with a FAST PATH ACTIVE / NO SPEEDUP verdict
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
