With this build (or possible earlier, as I hadn't updated for some time) ST3 stops rendering if I started it when the integrated gfx chip was active on my macbook and it then changes to the discrete. Changing back to the integrated makes it render again.
If I instead start ST3 with the discrete chip enabled and it switches to integrated, it's still rendering but is now very choppy. It's back to full speed again if the application is restarted or I switch back to discrete.
Reproducible via the gfxStatus app