What disk/folder is represented under "perfomance"?

[Anders Madsen]

And what disk should I clean to improve performance? (They are both quite crowded)

[reginaldStjohn]

I would clean all of them if they are getting full.  The most important one is where your audio gets recorded and saved. Easier but more costly is to add another HD and point your new projects to that new uncluttered HD.

[scook]

With tooltips enabled, hovering over the  disk space meter shows drive being used.

[John Vere]

What I'm seeing is your hard drive is almost full. At least that's what I always thought that icon is for. The other one below is how much memory your using.  You need to remove stuff to a back up drive and delete junk your not using.  

To check disk usage just open the my  Computer -- This PC   icon.

Edited December 16, 2020 by John Vere