http://msmvps.com/blogs/laflour/archive/2009/03/06/sharepoint-tip-20-do-you-know-about-site-objects-limitations-in-size.aspxWhen you plan the architecture of you SharePoint farm you should be aware about the following limitations in size of SharePoint objects. Keep your items below those numbers to have adequate performance, otherwise it degrades significantly if you overstepenCommunityServer 2008.5 SP2 (Build: 40407.4157)