Virtualizing panels are involved when an application’s performance needs to be improved. It provide a base panel for virtualization of children elements inside it. Instead of creating all the UI element which are inside an ItemControls, only the one which need to be displayed are created. Because the process of creating these elements is intensive, the use of a VirtualizingPanel makes an item controls display faster. The VirtualizingPanel comes with new features in WPF 4.5: two properties named ScrollUnit and CacheLength and virtualization on grouped data. In this post we will discover them in details. This post is a part of a serie on WPF 4.5 new features.