Question:
Are there specific recommendations for the maximum size of any database? For instance, does performance suffer if the database size is too large?

Answer:
Certainly, the amount of data in your database will affect performance. Remember though, that it is only one factor. Other important considerations include the number of users, hardware, design, and indexing scheme. In version 6.5, a database of more than 100GB was considered unmanageable. This had more to do with the bad performance of the maintenance tasks such as DBCC and backups than with anything else. In version 7, Microsoft is aiming to support databases as large as a terrabyte.