I found out when VideoCore is too hot it slows down.
In my main rendering thread when I don't need to do render I just use usleep and wait defined time instead of render the frame and call eglSwapBuffers. So I don't do rendering when I don't need it and Videocore cools down.
I use main render thread (60hz) as a timer for smooth movements in a scene. But when I use usleep instead of eglSwapBuffers I am not able to do precise 60hz cycle.
So my question is if there is a way how to wait for V-sync (as eglSwapBuffers does) but don't do swap buffers.