JupyterLab substaintially slower than Jupyter Notebook

Hi guys,

New to JupyterLab but have been using Jupyter Notebook for a while.
I just realize that JuypterLab is much slower than the notebook, for operations such as collapse/expand outputs. Wonder if there is any trick to mitigate?


Can you elaborate when you see this? In particular, what sizes of notebook are we talking about here? How many cells, and how big (in megabytes) are we talking? When you are talking about expanding/collapsing outputs, do you mean clicking the blue bar to the left of a cell to get the three dots?

Do you have an example notebook you could post somewhere so we could see what you mean?

Yes, I mean for “expanding/collapsing outputs”, licking the blue bar to the left of a cell to get the three dots. I use the same .ipynb file (small sized), and try in both JupyterLab and Jupyter Notebook(the shortcut is O, right?). Under Jupyter Notebook, the response is much faster. by comparison, under Jupyter Lab, I can notice the “slight” delay.

I just upgraded to Jupyter Lab 3.2.1 (Python 3.9) from Jupyter Lab 2.X (Python 3.8) and the new Jupyter Lab reacts MUCH slower than the old Jupyter Lab 2.X. Are others experiencing the same? Is there any way to speed it up?