After deploying Microsoft Office SharePoint Server 2007 in the corporate production environment, Microsoft IT noticed opportunities to enhance performance, especially long page render times, and spikes in disk I/O and CPU utilization. By working to discover root causes, Microsoft IT identified areas of opportunity for performance optimization, including the back-end SQL Server storage subsystem, and front-end IIS servers

http://download.microsoft.com/download/0/E/B/0EBA7263-A555-4279-B9DD-1720F0139A2E/SharePointOptimizationTWP.doc