How to: Configure the Maximum Number of Worker Threads (SQL Server Management Studio)
Use the max worker threads option to configure the number of worker threads available to SQL Server processes. SQL Server uses the native thread services of the Microsoft Windows 2000 and Windows Server 2003 operating systems so that one or more threads support each network that SQL Server supports simultaneously, another thread handles database checkpoints, and a pool of threads handles all users.
To configure the maximum number of worker threads
In Object Explorer, right-click a server and select Properties.
Click the Processors node.
In the Max worker threads box, type or select a value from 128 through 32767.
Use the max worker threads option to configure the number of worker threads available to SQL Server processes. The default setting for max worker threads is best for most systems. However, depending on your system configuration, setting max worker threads to a smaller value sometimes improves performance.