If you have enough space on the SSD, try that. If it is faster then you have learned something: the external drives are the problem.
In that case I would try these things:
- Clean the calibre database. Library / Library Maintenance / Check library. Might as well check the files while you are at it. The first step compacts the database.
- "Optimize" the external drive, however that is done on Win11. The goal here is to ensure that the various file system bits are co-located for speed.
- Ensure caching is enabled. See https://www.lacie.com/gb/en/support/...ve-in-windows/
- If the external drive is a USB plugin key, replace it with a 'real' drive.