Hi.
Here what Brecht said:
As I said before, Sampling settings in render Tab does not seem to influence Solid mode. I’m not sure if we can choose sample rate for Solid mode from somewhere else.
Anyway, I tested again 2.79 and jagged edges were always there, even in static view. So perhaps in 2.8 it is more noticeable because one can see the variation of jagged edges when there is movement, and when the edge gets better in static view.
Edit:
Ok, User Preferences > System > Viewport Quality. Set the value=0 and you will always get jagged edges in Solid mode, even in static view. So I suppose that with a high value of quality, the time it takes for jagged edges to display well may take longer in slow graphic cards, and therefore it will be more annoying.