Those SATA ports on the motherboard, again

[forumjoe]

I'm utterly confused by the BIOS's assignment of the Intel SATA ports on the P55 series mobos. It simply doesn't seem to make any sense.

On my P55-US3L mobo, the Intel SATA ports number six and are labeled SATA2_0 to SATA2_5. However, this is what the BIOS gives:-

IDE Channel 0 Master
IDE Channel 0 Slave
IDE Channel 1 Master
IDE Channel 1 Slave
IDE Channel 2 Master
IDE Channel 3 Master
IDE Channel 4 Master
IDE Channel 4 Slave
IDE Channel 5 Master
IDE Channel 5 Slave

Observe that these are not all master-slave pairs. Channels 2 and 3 are Masters only. Note also that this mobo also has a PATA IDE multi-pin port which, if used, will take up at least one of these masters or slaves. I've no intention of using PATA, though. I'll be using SATA, but in Native IDE mode.

According to the BIOS, therefore, there are 10 ports on which IDE devices can be used. Well, how come, as there are only six physical SATA ports, plus one multi-pin PATA port, on the mobo? Or do these 10 include the two Gigabyte chip-controlled SATA ports that also happen to be on the board? I'll not be using the Gigabyte SATA ports, as I won't be running RAID mode. If so, how on earth do you know which channels in the above BIOS list correspond to the physical port? Or doesn't that matter?

What's the significance of those two Master channels (Chs 2 and 3)? Why no slave channels for 2 and 3?

At present, I've got the HDD and my two optical drives on the first three of the Intel SATA physical ports. Putting the settings to Auto, this is how the BIOS assigns them:-

IDE Channel 0 Master - HDD (on SATA2_0 physical port)
IDE Channel 0 Slave - DVD-ROM (on SATA2_1 physical port)
IDE Channel 1 Master - DVD-RW (on SATA2_2 physical port)
IDE Channel 1 Slave
IDE Channel 2 Master
IDE Channel 3 Master
IDE Channel 4 Master
IDE Channel 4 Slave
IDE Channel 5 Master
IDE Channel 5 Slave

I've tried but it seems impossible to get the BIOS to assign these three drives to any of the other IDE channels. Even if I physically swap the connections to those further down, eg. SATA2_1 swapped to SATA2_2, and SATA2_2 swapped to SATA2_3, the BIOS still assigns those two drives to IDE Channel 0 Slave and IDE Channel 1 Master, respectively.

There seems to be no correspondence whatever between the physical ports on the board and the order in which the BIOS handles them as channels. Am I going nuts, or does this, in fact, makes some sort of perverse sense?

[Dark Mantis]

I'm utterly confused by the BIOS's assignment of the Intel SATA ports on the P55 series mobos. It simply doesn't seem to make any sense.

That's your first mistake...trying to make sense out of it!

I'll not be using the Gigabyte SATA ports, as I won't be running RAID mode.

The Gigabyte SATA ports are exactly the same as other SATA ports and can be used  by any SATA drive not necessarilly by RAID only drives.

There seems to be no correspondence whatever between the physical ports on the board and the order in which the BIOS handles them as channels.

You will notice that if you put any drives on the GSATA ports they will appear on a different channel.

[forumjoe]

You will notice that if you put any drives on the GSATA ports they will appear on a different channel.

There are only two physical Gigabyte SATA ports available on my mobo, though.

So, to separate my three drives out more, I could leave the HDD on SATA2_0, and connect the two optical drives into the two physical GSATA ports, then? Will it be predictable as to which channels the BIOS will assign the two optical drives?

According to the user manual, both the Intel and Gigabyte SATA controllers run at 3G bps, but does that mean that if any drives get assigned in master-slave pairs, they'll run slower than if they are assigned to independent channels? Remember, I'll not be using RAID. Are Channels 2 and 3 by any chance dedicated to Gigabyte SATA, and therefore that's why they're two Master channels and don't have slaves?

[Dark Mantis]

It really won't make any difference which ports the system allocates as they are all SATA and so don't come into the Master/Slave thing like IDE used to. The speeds won't change. I am not 100% sure what channels are used for the GSATA but as you suggest it could well be 2&3.