In a VB app. what is the effect on memory by using bound (dbcombo,dbgrid, etc ) and unbound (combo, etc) controls.

We can open database by using Data control at design time Or we can define it at runtime.
Which is more efficient and less memory consumption.

i have a form having several combo box and text box and grid . and they are linked with different tables in similat database. what is the vesy methid to connect it to database.