I had the same problem with an Infragistics Grid. The time of loading was 25 times slower than the DataGridView. I found an option in the Infragistics grid

this.grid.DisplayLayout.LoadStyle = Infragistics.Win.UltraWinGrid.LoadStyle.LoadOnDemand;

By default, this option is set on PreloadRows. Now with the property set on LoadOnDemand, my grid loads in 600 ms.

So I advise you to search the same kind of option in the DevExpress Grid. It may help you

David