Mesh.CreateContourCurves() in Rhino7 seems to be much slower than Rhino6

In Rhino7, Mesh.CreateContourCurves() or Rhino Command “Contour” are slower to compute than Rhino6, either in the plugin or in Grasshopper. what is the reason?
These two are test code. The code is actually the same.
Contours (95.7 KB)
Contours (96.9 KB)
Please change “Calculate” to true.
Thank you!

The mesh intersection code is different in Rhino 7 than in Rhino 6. It is much more accurate, but can be slower in some cases.

Grasshopper has a multi-thread Contour component. Have you tried it?

– Dale

Yes, I know there is. During the development process, I found that the API of R7 is relatively slow, and I am very curious about the reason. In actual development, I use multithreading.
I used a better solution, thanks!