MOSS 2007 / WSS 3  had a SharePoint Capacity Planning Tool to assist in planning capacity for a web farm and installation.  However, in SharePoint 2010 this tool has been deprecated. 

I have been looking around for guidance as to what might take the place of this tool for SharePoint 2010 installations. 

What I have found is there are a series of White Papers that Microsoft has published that are a good head start on capacity planning. 

The first link is one to the SharePoint Server 2010 performance and capacity test results and recommendations.  These are 9 documents that consist of laboratory setups and studies on SharePoint running in different configurations.  In one sense these are actually more helpful than the capacity planning tool in that there are real concrete numbers you can attach to recommendations, and they are for specific areas of the SharePoint product as well, such as Access Services, interacting with large lists, InfoPath, PerformancePoint, Search, Workflow and others.

One of the initially most helpful for me was the Divisional PortalCapacityPlanning.docx.  This document examines a typical multiple portal intranet setup.  It uses 4 server farm configurations – 1x1, 1x1x1, 2x1x1, and 3x1x1 with respect to capacity planning under load.  It gives specific hardware configurations for each of the servers, and the hardware configurations seem to be relatively standard in the industry, such as a for the WFE’s a Dell PE 2650 with 2 Quad Core 2.33Ghz processors and 8GB RAM. 

One other helpful element is that the test scenario is limited to a typical Intranet environment and does not have all of the add-on services configured that could skew results.  For each of the services they did a separate test set up and reported a separate result in another white paper.

Some other helpful information in the document is the construct of the load test itself.  The test represents a transactional mix of user activity that while it may not be completely representative of a particular environment does seem to represent a balanced use of different areas of the SharePoint product.

And the reporting results are good too – there are zones represented, like the “Green Zone” meaning that the server is operating within functional service limits.  There are also concrete numbers that help out as well, such as the numbers of Requests Per Second (RPS) that each of the configurations can handle. 

And there are real concrete results to report as well, backed up by the numbers.  For example, did you know that a 1x1x1 farm - (1 WFE, 1 App, and 1 SQL) can support a Green Zone number of 99 requests per second (RPS) or approximately 7000 users in the above configuration?  Or a 2x1x1 can support 191 RPS and approximately 13000 users?  Or a 3x1x1 can support 242 RPS and approximately 17000 users?

Or how about did you know that a 1x1 farm configuration is not really recommended for standard scenarios?  And that in a 1x1x1 AND the 2x1x1 setups the WFE servers are the bottleneck and it is not until you get to the 3x1x1 setups that the SQL Server disk I/O becomes the bottleneck?

Pretty cool stuff, if you ask me.   Some supportable data for our recommendations when we are out there helping users set up and configure SharePoint 2010.

Happy capacity planning!!!

Dave

PS – Other white papers also can be found at Technet under Performance and capacity technical case studies

Also, another great resource is the Technet Capacity Management For SharePoint Server 2010 page