Basically the P45 chipset supports only 6 SATA devices, so your motherboard manufacturer wanted to give the users up to 8 which requires an additional SATA controller. These 2 ports will work just like any other but if your trying to use RAID to pair disks together, these will not be able to communicate with the main 6 unless you use windows or software to combine volumes
D IKE E
Here you find how to use both orange and white ports as normal S-ATA-ports incl. hot plugging!