I've been battling sluggish rendering in PyCharm for months. I started by disabling all plugins that don't serve me at all, including the "AI" helpers. Bumped the max memory.
Nothing.
Switched to VS Code for a while, but it just fell short. Then I ordered a long overdue new Macbook Pro, for other reasons, but I was hoping that would alleviate the issue.
Nothing.
And then it hit me: the problem doesn't occur when I'm working on my laptop without an external monitor. I'm so incredibly relieved that it finally seems to be able to keep up.
How? This custom VM option: -Dsun.java2d.metal=false
That's it.