This object was bound to A Devexpress Grid. The time it takes to show query result on this grid is 1:40 (mm:ss)

The same object was bound to DataGridView. The result is nearly 3 (seconds)

I wonder why do I encounter with there is big difference ? Everyone test this condition easily.

This is definitely an issue when running in debugger mode in Visual Studio. Instead of running your application by pressing F5, try CTRL+F5 as that will run your application without the debugger - you should see a drastic improvement in performance.

Aaron