On Wednesday 22 August 2007, Alfred von Campe wrote:
As far as I know, all drives (2 hard disks and 2 optical drives) are on the same controller. Well, all 4 are plugged in to the motherboard of a Lenovo ThinkCentre M55 PC. There is no separate controller, unless there is more than one on the motherboard itself.
Many motherboards that have more than two SATA connectors put two on the SouthBridge's IDE-type controller, and the others on 'something else'. Usually, the 'something else' shows as a SCSI controller in Linux. How many SATA connectors are there?
I have seen a few motherboards use the Intel ICH ports as the first two, then put either a Promise or SiliconImage controller on the board to handle the other two or four ports (typically labeled as being 'RAID' ports). The ICH will show as /dev/hdx, and the SiI or Promise will show as /dev/sdx.