Slow rendering with a lot of columns

Hello guys, I'm using the UI-Grid v3.0.0-rc.21. I tested the code on Chrome and IE 11, on a Windows 7 with 8GB Ram. When I declare a lot of columns into the ui-grid the rendering freeze the web page until the grid is rendered. Is there a way to optimize the rendering of the grid with a lot of columns? Or is there a way to avoid the freeze of the web page so I can show a progress bar animated until the grid is rendered? Here below an example of the freezing of the web page when the grid is loading: http://plnkr.co/edit/e984mLFqa9o8XZqnGXEm?p=preview

Thank you so much!