Well you've got some options:
First, you could just disable the Marvell Controllers and SAS as bobkn suggested. But then you could not use the ports.
Or, you could go to Advanced Tab > Onboard Devices Configuration > Marvell SAS Controller > and change the mode (that I am assuming is presently set on RAID) to IDE.
Or, if you want hot-swapping capability you could change the Marvell mode to AHCI.
To run the controller in either AHCI or RAID mode you may need to install the Marvell SATA
drivers. You will find the
driver on your motherboard Installation DVD, or you can download them from the ASUS website.
When you boot there will be a brief delay as the Marvell Controller is initiated (about 1.5 sec), but you will eliminate the delay as the computer searches for the non-existent RAID driver.
Sorry if my descriptions of the BIOS setup is different from yours. I am running an older P6T and my hardware is different than yours. Just post any differences.