SharePoint 2010 Site Limits

Following are Site Limits for SharePoint 2010

• 500 million social tags, notes and ratings
• 30 million documents per library
• 30 million items in a list
• 2 million users per site collection
• 1 million alerts on Searches
• 1 million terms and terms sets (think metadata on steroids)
• 400 000 major versions per document
• 250 000 site and subsites per site collection
• 10 000 user groups per site collection
• 10 000 metadata tags recognised per item when searched
• 5000 documents or list items displayed per page
• 5000 blogs per site
• 5000 groups is how many each user can belong to
• 5000 users can be in one Active Directory group
• 2000 site collections per content database
• 2000 subsites under View All Site Content
• 1000 comments per blog post
• 1500 projects deliverables per Project Server plan
• 1800 documents in a SharePoint Workspace
• 100 items at a time you can bulk edit
• 25 web parts per page / wiki
• 10 people editing a Word or PowerPoint document at the same time
• 100 GB space per site collection
• 2 GB per document upload size

Source : TechNet