exactly, i work at the moment for a project with 2048*768 (2 screens). to be able to make fullscreen motionblur i need to snap 2048*2048 which puts cpu to 98%.
anyway i found a workaround for the workaround which delivers a good result for just 10% cpu; i compose the fullscreen motionblur out of 2* 1024*1024 snaps, textured on 2 squares.
i forgot to mention that i also had to scale down the gemwin to 1600 * 600 for the 10% cpu
e