The TempDB only has a single data file error is detected in the Database Health Monitor Quick Scan Report.
There are many recommendations out there as to how many TempDB files your database has. The general consensus is that you should have the same number of TempDB files as you have cores on your SQL Server with a maximum of 8.
What if TempDB only has a single data file
When TempDB only has a single data file, that single file can be a throttle point for all queries that use TempDB in one way or another. Having multiple TempDB files will allow for more throughput on items that are placed in TempDB by reducing the contention over a single drive.
What if I only have one core? You probably have more issues besides TempDB if you only have one core.
Stedman Solutions, the provider of the Database Health Monitor Application offers consulting solutions, and can help with getting your TempDB set up correctly, or any other database administration issues you may have.