Hyrule Field Twilight Princess - Something really weird I noticed

I registered today, so hi everyone

I was recently playing TP on Dolphin 3.5-420-dirty-ICC revision, with the current laptop hardware:

i7 3630qm 3.4GHz
GTX675MX
16GB RAM (for 3d design basically...)

and noticed that when you start the game, for example, in hyrule field, the game runs at 23-24-25 FPS with the ZTP hack and some AR Codes I used for the music that are supposed to low the background. The minimap works perfect.



So long, it's basically what I have seen in the forum, but...


Now, the weird stuff. when you open ONE of the graphics menus, the fps become solid 30, no slowdowns, perfect performance, with the sacrifice of some stuff of the minimap.



Does someone know exactly what's happening lol?

It's funny that It actually runs fullspeed after all that stuff.
Thank you.