Originally Posted by James5mith
Unless something has changed, each SATA port is a unique point to point connection to the controller. I.e. There is no channel sharing like there was in IDE.
Thus if you have 6 SATA connectors, you have 6 channels.
Perhaps things have changed since SATA was first introduced though.
I should have worded that differently, trying to make it simple which is not always the correct thing to do.
The problem on this board and others is that disks attached to ports SATA0 and SATA1 may not actually correspond to those channels. In other words, Disk 0 may not be assigned to the hard disk on SATA0, and Disk 1 may not be assigned to the Optical disk on SATA1 in his example. You would expect the disk-assignment numbers on the ports to match the corresponding SATA channel numbers but this is not always the case depending on the BIOS design.
There is no assurance of a consistent relationship between PnP enumeration and the order of disks that are detected during setup (POST). Devices are presented to the system in the order in which they are enumerated and not by channel or port number. Therefore, the disk-assignment numbers may change between startups or when additional disks are added to the system.
On this particular board, having the optical drive on port one resulted in it actually being enumerated first, which normally would not be a problem, but these Sony drives with early firmware have not played nice with the Intel controllers. The system sees the drive and then tries to assign it a channel which does not occur and the BIOS run routine freezes at that point.
Changing the port assignment will usually allow the hard drive to be recognized and enumerated first and the system will either still throw the code, take a while and finally recognize the Sony Optical drive, or it will continue the POST process in most instances.
Either way, at least he can boot at this point. In the end, the channel numbers will change depending on AHCI, RAID, or Enhanced IDE settings for the drives. That is why at times you look in the BIOS and see that your primary drive is on SATA channel three even though you have it plugged into port 0 on the board.