You can try this in Help > Edit VM Options
-Xmx8000m
-Dnosplash=true
Not sure if that is the correct anymore as I switched away from it, but it should deactivate some of the gpu rendering. Or just google disable hardware rendering intellij. I would also use Loupe or some zoom tool to see how the text renders and test some monitor resolution and font size that seems sharp, as you'll stare at text for hours.