We have a situation with an very large and active on-prem installation with the Audit Trail logs. In exploring the options we realized that we could not find any information on best practices. Hopefully, this thread will be able to document some good ideas and approaches.

In this case, we are generating between 4 and 6 50 MB files per day, not using compression.  Here are our questions:

What is the performance hit in reporting when compression is turned on? What do we gain in terms of space?

The "look-back" is 360 days.  One idea is to create a new folder for the logs every quarter, and then define a search catalog search catalog for that folder. The thinking is that the searches for more recent data might be faster if the catalog is smaller, or if the search engine does not need to span more data. Is that an accurate way of looking at this?

What is the performance hit if the Archive folder is moved to a network drive? (Approximate, realizing that there are many factors.)