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SQL Server MAXDOP and parallelism

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At our company, we have a 4 core blade running SQL Server 2008 Enterprise Edition. This is a very, very busy SQL Server and is running on HP EVA hardware, so the I/O is not an issue. We have over 50 warehouses all running SQL Server 2008 and replicating data to/from this primary database. This database is also used by our website, webservices and import/export applications. The only thing this database does not serve is our SSRS reports, which are hosted on another blade. What is an issue, however, are the CPU's. They were very busy. To help with this we can play around with two settings on SQL Server: MAXDOP (Max degree of parallelism) Cost threshold for parallelism Our DBA and I had a few discussions around this recently. Read plenty of articles on it, such as Adam Machanic On a normal system, leaving these settings alone are fine, but on a very very busy system you need to change them. MAXDOP=1. What this does is to always use 1 core for the query. MAXDOP=0, Cost...