Ext JS 4's brand new grid supports infinite scrolling, which enables you to load any number of records into a grid without paging.
The new grid uses a virtualized scrolling system to handle potentially infinite data sets without any impact on client side performance.
This example illustrates loading of all the records up front and buffering the rendering, but sorting is not enabled. For an example illustrating dynamically loading and sorting data take a look at the Forum example.
The code is not minified, see buffer-grid.js