With all the enthu we install SharePoint (2007/2010) on our system for development and then we realize that it is the reason for making our system slow. Then we start thinking that we need far more better system with lots of GB of RAM :-) But the main point is that SharePoint is a horse that is trying to pull the elephant. Following reasons contributes to my point:
- Bottlenecks of SQL Server
- Our old friend IIS and its services for every web application that we create
- SharePoint surface area is scattered so far and wide that leads to churning, when complex pages experience latency because of needed data is scattered.
In order to increase the performance, Microsoft has came up with SharePoint Performance Optimization: How Microsoft IT Increases Availability and Decreases Rendering Time of SharePoint Sites. This is a 27 page document which you can download from here
The main juice comes after the how to find out which part of the SharePoint system has a problem. I think, and I am very much sure that, it's not "one part". When we have lots and lots of users, complex sites, huge numbers of documents (word, excel, pdf, etc), this spawns the performance issues which then becomes very difficult to stop and due to this overload critical servers goes for a toss.
Following are certain links which talks about this in more detail
and describes the steps to improve the performanceSharePoint Performance Optimization In 10 Steps for the IT Professional
SharePoint 2010: Improve SharePoint 2010 Performance with RBS
Tools to Optimize the Performance of SharePoint Server 2010