yesterday i tried a quick painting from this image:

i used this as tracing image with opacity of 64%

Program used in fullscreen @: 3840x1600

Windows 7 / x64
AMD FX 6200 Six Core @ 3.80 GHz
Ram 26GB
Nvidia GTX 1060

at all, best settings for a great Painting but---------> if i zoom or try to move the background while drawing i have a huge lag.

any suggestions?