Single figure FPS on top end Win8.1 laptop after changing text size in system resolution settings

Unless I put the Custom Text size to Recommended (200%) I get 0-5 FPS in Minecraft.

At the recommended setting (as per the screen resolution setting) I am getting 60FPS with many other apps (Chrome, Visual Studio etc) open and services (Oracle, SQL Server) running.

At any other setting Minecraft is unusable.

Keywords:
custom sizing, retina, slow, screen resolution, win8.1 win8,