Comment 7 for bug 1822223

Your computer doesn't have enough video memory to handle two high-DPI screens with 4x AA. 4x supersampling AA mode just renders the image in 4x larger resolution and then scales it down - so for a 3360x2100 display, the actual buffer size is 13340x8400x3 ~~ 300 MB. Kicad needs more than one such buffer to work.

BTW, even with AA off the schematics look rather smooth on my Macbook with retina (set in native resolution, without scaling) and with 2xAA they look almost perfect.

Tom