SDL2 slow on mac pro?

The rectangle should move across the window in one seconds, instead it’s taking multi seconds.
setting it to SDL_RENDERER_SOFTWARE is much faster.
here is the complete code, .
I asked this question on reddit too, and a guy compiled it on windows and said it was working as expected. so i guess it’s a mac issue.
here is the question on reddit

running valgrind ./rect yields this

Perhaps VSync is getting enabled? That can limit the app’s framerate.

– David L.