If you are experiencing performance issues in your CRM Online, a first step in identifying the source of a performance issue is to determine whether or not network factors (mainly bandwidth or latency) seem to be part of the problem.
Low bandwidth and high latency will negatively impact the end-user experience in Microsoft Dynamics CRM Online, so be sure to get a baseline reading of WAN performance at the initiation of the troubleshooting process.
The Microsoft Dynamics CRM Product Group has developed a Microsoft Dynamics CRM Online Network Performance tool to gather client network configuration data. The tool provides insight into the network conditions under which Microsoft Dynamics CRM client is operating.To run the Microsoft Dynamics CRM Online Network Performance tool:
Microsoft Dynamics CRM is designed to work best over networks with latency under 150 milliseconds.
You can read much more about optimization in the white paper from Microsoft "Optimizing and Maintaining Client Performance for Microsoft Dynamics CRM 2011 and Microsoft Dynamics CRM Online"
Note - determining the instance and unique organisation name:
Depending on the which part of the world your CRM Online tenant is hosted in the crm instance is either crm, crm4 or crm5:
To determine the unique organization name of your CRM Online - goto to Settings -> Customizations -> Developer Resources