When your WPF app needs to render hundreds of thousands or even 1 million+ rows most grids start to choke. Scrolling stutters, the UI freezes, and users lose trust in the application. In this guide, we’ll walk through how to render 1,000,000 rows in WPF without freezing the UI using Xceed DataGrid for WPF. We’ll compare a naive WPF grid to Xceed DataGrid with async data virtualization, show a simple benchmark, and give you code you can drop into your own app.