lightweight pooling Option
Use the lightweight pooling option to provide a means of reducing the system overhead associated with the excessive context switching sometimes seen in symmetric multiprocessing (SMP) environments. When excessive context switching is present, lightweight pooling can provide better throughput by performing the context switching inline, thus helping to reduce user/kernel ring transitions.
Setting lightweight pooling to 1 causes Microsoft SQL Server to switch to fiber mode scheduling. The default value for this option is 0.
The lightweight pooling option is an advanced option. If you are using the sp_configure system stored procedure to change the setting, you can change lightweight pooling only when show advanced options is set to 1. The setting takes effect after the server is restarted.
Lightweight pooling is not supported for Microsoft Windows 2000 and Microsoft Windows XP. Windows Server 2003 provides full support for lightweight pooling.
Common language runtime (CLR) execution is not supported under lightweight pooling. Disable one of two options: "clr enabled" or "lightweight pooling.