Adding my two cents:
I have a very large library with over 1,000,000 tracks and over 75,000 albums with about 11,000 of those albums on Qobuz and Tidal, which means about 64,000 local albums. All my local music is stored on USB drives connected to a Window 10 computer. I also have over 10 endpoints of various types, i.e. Roon Ready, Squeezebox, Chromecast, AirPlay, etc.
Details:
i7-7700K CPU @ 4.20GHz
64 GB RAM
Roon database is on an NVMe SSD drive
First and foremost Roon is a big time memory HOG. I recently upgraded the RAM from 32GB to the present 64GB because of performance issues with Roon. The increase in RAM has definitely improved Roon performance. I still find that Roon needs to be restarted very couple of days since over time Roon’s performance gets worse, e.g. slow loading, slow searches, slow Focus and slow “Filter” searches. When I restart Roon I get the “database update” message about every third time. Once restarted Roon works great.
The above paragraph is not meant as a complaint but rather just as information. The fact that Roon can manage such a large library is amazing. I really don’t mind the occasional hiccups and restarts since I know that things are not “broken” and everything will work as good as new after a restart.