firstly I'm not going to use on-board graphics..
other than that and the name of the chip-set, what difference will i find performance wise between the following motherboards:
they all look the same to me and have the same specs too..
The new 8xx chip set supports SATA3 and USB3 which eventually is going to give more performance if you have a SATA3 disk drive or USB3 peripheral connected to those. CPU performance on those boards is going to be similar.