I use an Acer Aspire M1640 with a Hitachi 250gb IDE hard drive and the DVD drive that came with the Acer, i'm not sure what make, but it's SATA. The motherboard is an Acer MCP73, the northbridge is Geforce 7050 and southbridge is nForce 620i. I found a thread about how to install for nForce but it didn't say anything about 620i, just 610i and 630i.
I've tried to change to AHCI but my BIOS doesn't give me the option. When I change so RAID the DVD drive doesn't boot. I think I just have to accept that it's not gonna happen for me