Windows 7: Sata Disk 0 and Disk 1

For a long while I ran just one HD (Sata) on my machine. It was connected to Sata 1 on the MB and appeared as Disk 0 in Disk Managment. I just connected another Sata drive to Sata 2 on the MB. It shows up as Disk 0 and the original as Disk 1. I had thought the reverse should be true -- Original still as Disk 0 and the new as Disk 1.

BIOS shows the original connected to IDE 3 Master and the added one connected to IDE 3 Slave.

The system works fine with all the partitions and their drive letters I had assigned to them correct.

No big deal. I just wonder why the Disk Management disk numbers appear as they do.



Would someone please help me understand?

Thank you.

This is one of those things that I don't think anyone has really figured out. You're not the first to ask about it, and from the last thread I saw about it pretty sure there was no definitive answer as to why. At the end of the day it will make you wonder why, but it also has no affect on how anything runs. You can sit and rearrange the cables to the motherboard all day long and you might hit the combination that will change them around, but not worth the aggravation.

Thank you.

So I guess I will right it off as one of those "Life's Imponderables."

There's no mystery about it, if I am understanding your question. The numbers in Disk Management have no relation to the physical ports. If a motherboard has six SATA ports, and the primary hard drive is plugged into the sixth port (SATA5), it will still show as Disk 0 in Disk Management.

And that is pretty much what happened. The original disk is in Sata 1 it appeared as Disk 0. When I put the second disk on Sata 2 it showed as Disk 0 and the original disk in Sata 1(the one that showed as Disk 0) showed as Disk 1.

I have had times on the same system where a clean install will show the drives in a different order (within Windows). As long as the drive letters are assigned properly, it won't cause any issues.

What then makes the primary disk primary? Is it the simple fact that that disk has an operating system thus it is the primary? What if I install a second HD that also has an operating system installed?

I had the same issue, installing the ahci drivers for the sata controller sorted them correctly.

I'm not quite sure whether I'm absolutely correct, but as far as I'm aware the BIOS recognises the drive that Windows is on as Drive 0.

So even if you connect the Windows drive to SATA 1 it will still show as Drive 0 in disk management.

Windows will see the HD Drive Disk0 when corrected to the first Sata port with a HD Drive. On Some MOBO the first Sata port is marked Sata 0 or Sata 1.
But if you have a IDE HD Drive also corrected, Windows will see the IDE as Disk0.