TempDB is one of the most important system databases of SQL Server.
There are many database operations in TempDB like GROUP BY, ORDER BY, UNION, online re-indexing, multiple active record sets, user-created temporary objects, internal temporary objects and version stores.
So if the tempdb is located on slow disk like sas or sata, these operations will be very slow.
If TempDB is located on fast disk like SSD or Flash, you will see extra SQL Server Performance.
You can change TempDB file location like following query.
USE master GO ALTER DATABASE tempdb MODIFY FILE (NAME = tempdev, FILENAME = 'E:\TEMP\tempdb.mdf') GO