I have some graphics related problem but only if dual monitor is turned on. If I plug only one monitor into graphic cards there is no problem,
With 2 monitors and 2 graphics cards I have slow and largish only one monitor. very strange?
also, I have Sierra 10.12.6 on second ssd with no such problems never before.
web driver 158 I think, I can't install only other it said non-compatible version of driver.
attached is some screenshots. for example youtube page on 2 different monitors - on one graphic is fine and other very strange like half of page is not loaded properly ... but it's just same window displayed on 2 different monitors