Hi there,
I too am having the same issue with the ATI 5770 card. It takes 34 secs to find the operating system to boot.
I tested with another graphics card and it immediately found the operating system and booted fine. My mother board is the GA-Z68X-UD7-B3
It would be great if someone knows how to address this issue.
5 mins is very long though, your boot priority is Hard drive and not CD or USB in the bios setup?