There are full updates and partial updates. The former involves refreshing the whole display multiple times to remove ghosting, and a complete redraw. The latter is a targeted change at specific coordinates, which typically involves going from white to black. Very fast, but it's a single point/block at a time.
I do wish there was a reasonably priced color remarkable equivalent. Very frequently, I start reading a paper on the remarkable and have to bail when a chart distinguishes lines by color.
Remarkable owner here. RM display doesn't anti-alias actual pen strokes, pretty sure this makes the screen refresh faster. Everything else that is anti-alias tho is a bit slower to refresh.
Why is the ReMarkable 2 screen able to follow your pen stroke with such low latency, then?