Comment 18 for bug 879762

KiCad is somewhat special in exercising video drivers and graphics framework because of great number of primitives redrawn on every zoom or drawing operation. Intel shared memory GPUs work quite fast in this kind of immediate mode drawing compared to discrete GPUs which need a bus transaction for every operation. The problem is similar to disk I/O in PIO mode compared to DMA. DMA is fast and smart, but needs quite a lot of support code to work. KiCad drawing is currently in the PIO mode, but the DMA version is in the works:

https://code.launchpad.net/~kicad-testing-committers/kicad/kicad-gal