what is the difference in performance with 9800 pro using 4xAGP and 8xAGP

[Jowin]

I have brought a new ATI 9800 pro from america, i wont get it for 2 weeks though , and im just wondering what the difference in performance will be using a 4xAGP slot, like i have, compared to an 8xAGP slot. Hopefuly it wont make much difference but if it makes shed loads of difference i might have to get a new motherboard

thanks for any help

Jowin

[Tweaked!]

I have not seen anything that indicates that 8x is any better than 4x. Everyone that has commented about it has stated that they cannot tell a difference.