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I've a gigabyte GA-M720-US3 motherboard. Recently, I noticed the following during boot:

IDE channel 0 Master (none)
IDE channel 0 Slave (none)
IDE channel 2 Master (my hdd)
IDE channel 2 Slave (my dvd drive)
IDE channel 3 Master (none)
IDE channel 3 Slave (none)

Of course, the same information is contained in the BIOS/CMOS. The HDD is connected to the mobo via a SATA(2?) cable at the port(?) labeled SATA2_0. The DVD drive is connected by a similar cable at SATA2_1.

  1. Why doesn't the information displayed during the boot and in BIOS reflect how I plugged the cables in? I mean, why "none" for channel 0 when there is something in SATA2_0. (or is that serious naivete on my part!?)

  2. Where's Channel 1 master and slave?

  3. Since these are SATA cables and not the IDE ribbons from a time ago, why the whole master/slave declaration during boot and in BIOS?

  4. Should my BIOS reflect the fact that these are SATA cables? I mean, in BIOS, should the "Onchip SATA mode IDE" be set to RAID or AHCI instead of IDE?

Any replies, answers, suggestions, links, tips will be much appreciated. Thank you in advance!

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up vote 0 down vote accepted
  1. I think the "channel" concept is more or less independent of the port numbering.

  2. Don't know the technical details behind why the numbering scheme is the way it is, but it's nothing to worry about.

  3. The IDE setting is generally the default, because it works with the largest range of devices - a SATA drive (HD or optical) can pretend to be IDE, but not the other way around. What you see is how the motherboard/BIOS chose to map its SATA input to an IDE equivalent.

  4. If you wish to run SATA rather than IDE, you need to set it in BIOS yourself. A few tips:

    • AHCI is the setting you want. (See Wikipedia for RAID.)
    • If you have an older OS (ex. Win XP) switching to AHCI will prevent you from booting, you would need to reinstall Win XP with a set of dedicated drivers.
    • On many motherboards there is only one setting for the whole board, so it may work only if all your devices are SATA.
    • I believe the switch is unproblematic from Windows Vista onwards, I know that it works in recent Ubuntu.
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Most likely because the department that wrote the bios did not talk to the department that engineered the motherboard, the department that wrote the manual did not talk to anyone.

The Gigabyte docs for that board show the Sata ports as 0 thru 5 on page 20

This manual is a bit confusing when spelling out the Sata ports on the motherboard, seems to be no continuity.

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