OSX trackpad mouse event not smooth

When I listen to the mousemove events inside a graphics view, using Apple magic trackpad on an iMac, I get a very slow rate of updates. Somehow it seems worse when I render OpenGL in the scene, though I am not totally sure about it.

I attach a simple example code that shows the problem: click and drag the red triangle works fine with the mouse, but is extremely slow with the trackpad.

I also tested on linux where it works fine.