Why sturcture diffusion inference is much faster than Stable Diffusion original?

[JamesSand]

Thanks for the great work. When I was testing the average inference speed of Stable Diffusion and this work. I found that it takes approx 7s for sd1.4 to generate 1 image, and only 5s for this codevase to generate 1 image. Why would this happen? I have made sure that both models are using ddim sampler.