When the graph editor is maximized by double clicking the background, there's latency related to the number of nodes on screen when in full screen mode. However, the graph is fine when it's docked.
Here's my graph at 0.4x zoom:
If I pop out the graph as a free floating window the speed is buttery smooth as well. However, if I resize the graph so that the graph inspector sidebar becomes visible, performance suddenly tanks.
I don't recall this being an issue in 1.3... but I wasn't using the expanded view as often as I am now.
Customer support service by UserEcho