So this is the most critical section of the level where the performance can drop below 30 fps.

The first number and the 4th number together represent the time it takes the 1st sh2 to complete a frame (at the beginning of the video is 26.800 + 4.004 ≈ 31 ms)

The second number is the time the time waiting for the 2nd sh2 to complete its tasks, though out the whole video hoovers around 0.004 ms (so no waiting).

And the 3rd one is the time the CPU is halted waiting for the next vsync (at the beginning 18.2 ms). This is the critical number, if this goes above 16.6ms it means the VDP1 is taking longer than 33.3 ms to render the frame and hence forcing the whole console to wait for the next vsync dropping the frame rate to 20. Currently it seems VDP1 takes up to 7 ms more than what it should, not great news XD.
I have already taken all the basic measures you can:
•	move to vdp2 whatever you can
•	make sure the first vertex starts rendering inside the screen boundaries
•	activate pre-clipping if the polygon is big enough and is out
•	activate HSS for downscaled polygons

From the VDP1 side, I don’t think there is much more it can be done, (unless I decrease texture quality or get rid gouraud) so the only solution is to make sure the CPUs finish faster leaving more room for VDP1 to complete its tasks.

At the beginning of the week the CPU in this area was also above the 33 ms threshold (≈ 36 ms), I offloaded some subdivision code to the CPU and moved a critical function to ASM, that brought back 5ms. There is still some room to move things to the 2nd SH2 but if I move too much code I might have some problems in other areas where the 2nd SH2 might be closer to the limit.

I still have some critical functions that could be converted to asm. Not sure if all that is going to be enough to get 7ms back, but in any case, I have implemented frame independent physics and animation so in case there are occasional drops it won’t affect much the experience.

This extremely fragile balance and nit-picking is sometimes underwhelming but unfortunately necessary to achieve decent performance in this console. The plan was to start next week with PS1 but I want to give this one more try.