Update: Note that with the introduction of UR10 for CRM 2011, there have been some changes to the EnableRetrieveMultipleOptimization (ERMO) setting. See the updated KB article here: http://support.microsoft.com/kb/2535245
There is an enhanced setting (EnableRetrieveMultipleOptimization) that CRM 2011 Online customers can enable to decrease the duration of certain long running queries (ultimately improving performance if the customer is running into the issue). The issue is magnified for customers that are accessing views that contain a larger set of data (ex. > 100,000). End users will only see this issue if they have a CRM security role that has business unit or parent: business unit read access on the entity in question. This is a performance issue that would occur for certain users in one area of the product (consistently sluggish). If things perform well one minute, and are slower the next, that’s likely something else entirely. While not every CRM Online customer will need to enable this fix, there will be a number of customers that will see positive performance improvements if they do implement this.
***The EnableRetrieveMultipleOptimization setting can have the same effects in a CRM 2011 on-premise environment by enabling it through a registry key.***
Requesting the fix:
If you have a Microsoft Dynamics CRM 2011 OnPremise deployment, the KB article to follow for setitng the registry key value is support.microsoft.com/.../2535245, "You experience slow performance when you perform RetrieveMultiple queries on large datasets in Microsoft Dynamics CRM 2011"