FLUX.2-klein's slow generation speed

[daniandtheweb]

I've been testing FLUX.2-klein in both the 4B and 9B variants and the generation speed is unusually slow (I expect generation to be slower than pytorch but this much seems wrong).

Here's some of the results:

FLUX.2-klein-4B: 1024x1024, 4 steps, cfg 1
ComfyUI: 5s
stable-diffusion.cpp: 25s (tested with Vulkan and ROCm)

In comparison the SDXL difference is only 5 seconds for a 1024x1024, 20 steps image: 10s ComfyUI, 15s stable-diffusion.cpp.

Is it just me or has anyone else noticed a similar behavior?