It is both frustrating and unnecessary to endure an under-performing BI system. If you are on the BI DIY road you will find several articles and whitepapers on this website that may help you by pointing you in the right direction.
Performance optimised code for Web Intelligence is intrinsically tied into a relationship with the SAP BusinessObjects universe. There is a short article on this entitled: Increased Performance Through Optimised Universe Design. There are also various techniques that can be employed such as Improving Web Intelligence Deep Drilling Capabilities with Vertical Hierarchies.
However, for optimised performance the data warehouse design must be given serious thought, consider The Aggregate Advantage. Similar principles hold true if you are using the SAP Business Information Warehouse with Web Intelligence and need Cube and Query Design for Performance Boost.
It is always advisable to give consideration to Sizing, Hardware & Licensing Models before implementing your BI system, especially where the full SAP BusinessObjects Enterprise is to be deployed.
We will be adding many more whitepapers and helpful information as time progresses and you may also find our videos on this website and YouTube of some help. But, if you are experiencing issues that you cannot seem to rectify you can engage us via our Contact Page.