I run a TSQL query using SQL Management Studio and have noticed the performance is significantly degraded when running on a 4-processor (quad) machine then when running on a (2-processor) dual-core machine. It is a fairly simple query with a 2 way join that returns over 1 million rows. On a Intel Dual-Core 2.0 GHZ machine, the query takes ~14 seconds. On a Intel 4-CPU 3.2 GHZ machine, the query takes ~24 seconds. The results are always consistent. Both machines are running Windows 2003 with SP2. Both machines are running SQL Server 2005 with SP2. Both machines have 4 GIG of ram. Both machines have exactly the same database schema. The execution plans for the query on both machines are identical. I have noticed, however, that if I run the query remotely to the quad machine from the Dual_Core machine, the query takes ~14 seconds, the same time it would take running locally on a dual-core machine. So it doesn't seem there is a problem with the database or server component of SQL Server. I have configured SQL Server to use only 1 or 2 CPU's on the quad machine but it did not change the results. I have also noticed that in Task Manager, the System Idle time is about 60% on the Quad machine; the SQL Mgmt. Studio was getting about 30%. On the Dual-Core machine, the numbers were almost reverse: System Idle time is about 30% and SQL Mgmt Studio was about 60%. It's almost as if the process is not getting enough cpu time. Is there any explanation and resolution for this degraded performance on a 4-CPU system?