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After you enable the AlwaysOn Availability Group feature in Microsoft SQL Server 2012 on a Windows Server 2008 R2-based failover cluster, using local and remote Availability Group database replicas, the failover time to the local replica takes longer than expected.
Note This issue occurs because of inter-node communication within the cluster.

To improve the performance of the “AlwaysOn Availability Group” feature in SQL Server 2012 is available for Windows Server 2008 R2.

Important : You must restart the computer after you apply this hotfix

To download:  http://support.microsoft.com/kb/2687741/en-us