Consider the following scenario:
You use Resource Governor in Microsoft SQL Server 2014.
You create a resource pool by specifying the CAP_CPU_PERCENT argument with a value that's much less than the default value. For example, the default value is 100, and you specify a value of 20.
You create a workload group that uses the given resource pool.
You connect to the instance of SQL Server, and the connection is classified to consume the given workload group.
You run queries through the connection.
In this scenario, the CPU usage is higher than expected, and you experience decreased performance when SQL Server process queries.
The issue was first fixed in the following cumulative updates of SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. We recommend that you download and install the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.