Microsoft has announced the increase of the site collection size limit from 1 TB to 25 TB for Office 365.
A Site Collection in SharePoint is an important logical boundary in that it provides a separated zone for sites and content. The Site Collection in SharePoint controls a number of settings, taxonomy features, permissions and navigation concepts.
In previous versions of SharePoint, the Site Collection size was limited by the size of the content database. Content databases were stored in SQL Server and the recommended limit for SharePoint 2007 and 2010 was 100 GB in order to facilitate easy backup and restore of the database. In SharePoint 2013, the recommended limit was increased to 200 GB with no hard limits on the database size. In SharePoint 2016, the content database can be 1 TB or greater, with the limitation being your backup/restore solution’s ability to manage the size of the database.
With smaller Site Collection boundaries, organizations were sometimes forced to carve up their collaboration sites into multiple site collections in order to fit within the recommended size limits. This created some odd governance issues as organizations split up site collections by department, function, etc. without understanding the complexity of doing so. In many organizations where conduct migrations from previous versions, we found hundreds of site collections.
With Office 365, Microsoft is now raising the bar again so that a single site collection can store up to 25 TB. This should simplify collaboration site deployment in particular so that all site collections can be managed within a single site collection if desired. Given files are also increasing in size (for example, with large video files or engineering files that can take up hundreds of megabytes) the additional room will be welcome to some organizations.