SQL Server in Fiber Mode
Every now and again, somebody finds the "Fiber Mode" setting switch in Server Properties.
If you read the 2 lines that BOL has about it, you actually get to think that it is a good idea. After reading the following article from Ken Henderson (Microsoft), I think you might change your mind:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsqldev/html/sqldev_02152005.asp?frame=true
While you are there, read his articles on SQL Server Memory Architecture and User Mode Scheduler. Good insight into how some things work.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsqldev/html/Sqldev_02252004.asp?frame=true
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsqldev/html/sqldev_01262004.asp?frame=true