Analytics Software

Oracle says, Using a 3-tier architecture for your application improves the performance. Reason: Middle tier takes all burden of data fetching, storing & serving. But I've noticed that this is not true. When we are working on Desktop version its fast, be it opening the workbook, moving between worksheets, saving the workbook, etc. Moreover, 4i plus some times doesn't response after clicking save button & the only option is to close the session. Similarly sometimes when we cancel the running query it stops responding, although task manager says its running but actually its not.
I am searching for the answers to these Questions & many more like this.
Anyone has any ideas, please give your expert Opinions.

Thanks