agp slot diff?

[moosey]

What is the difference if a mobo has an AGP 4x slot or an AGP PRO slot?

 

[vss1980]

AGP Pro slots were made to allow the graphics cards to take more power if necessary, by giving it extra connections (extending the actual connector in both directions) for power contacts.

Technically I suppose they can also be keyed to operate with certain voltages.