https://www.kickstarter.com/projects/krita/krita-free-paint-app-lets-make-it-faster-than-phot/comments?cursor=9824296#comment-9824295 "Hi Mira-Maia! Part of the problem comparting Krita on Linux and on Windows is that Windows is, indeed, a slower platform. The OpenGL drivers are frequently broken, the file system is slow and even drawing graphics without using OpenGL is measurably slower. That said, we're doing all we can to make Krita as fast as possible!"