A significant percentage of web sites utilize PHP as a platform for dynamic content. During the development of Windows 2008, Microsoft included improvements that enable PHP to run more efficiently than previous Windows releases. This article describes how to tune Windows 2008, IIS 7.0 and PHP for environments with a single site and high concurrent user traffic.
Windows 2008 and IIS 7.0 have new features and optimizations that allow PHP to run more efficiently and robustly. The most significant improvement Microsoft made was to update the CGI support in IIS 7.0 to conform to the Fast CGI standard. Fast CGI saves a process create/destroy operation per request by pooling and reusing multiple worker processes. This translates into significant performance improvements for PHP applications on Windows.
By default, the Fast CGI support in IIS 7.0 is configured to be conservative when allocating resources in order to best support the scenario where hundreds of web sites are running on a single physical server. This was thought to be the most important deployment environment for PHP on Windows. This article describes the differences between tuning a Windows server for a multi-site scenario versus a single site scenario assuming high overall traffic.