[mv2devnull]

AFAIK,

The "Gigabyte SATA2" -chip is a JMicron 363 set to provide an IDE channel, and couple SATA devices. Those "SATA devices" happen to be Silicon Image 5723 chips. A SiI 5723 provides minimal hardware RAID0/1 functionality, but probably at some cost. And that cost seems to be lack of support for ATAPI devices, such as CD/DVD.

Asus has P45 boards with SiI 5723 behind Marvell 6121 chip. (They have had JMicron 363 on their earlier boards.) And Asus documentation stresses that on their board the SiI 5723 does not support ATAPI.

Now that I think, I've never even looked at documentation of hardware RAID HBA's for whether they allow connection of non-HDD on them. But I do doubt that they would.

That leaves the IDE channel on 363, and the SATA ports on the ICH10R, both versatile enough to support ATAPI.