BIOS setup for Z77X-UP5H TH Help Request

[skapplin]

I have the above system running just perfectly with one exception. This is the boot drive priority configuration. I have four drives installed as follows:

OWC 120 GB SSD - intended as the boot device. Setup for 6.0 Gb/s.
Seagate 1 TB hard drive - used as the main Home drive. Setup for 6.0 Gb/s.
Seagate 250 GB notebook drive - an extra drive to be used for emergencies.
Pioneer DVD drive.

The boot drive must not be a UEFI drive, but must be a Legacy P0, P1, etc. pre-fixed drive. The problem is that only the OWC SSD and the DVD drive are Legacy pre-fixed as P1 and P2. Now that's fine since the box boots from the SSD as intended. But the other two hard drives are UEFI pre-fixed so that neither can be used as a boot drive. No matter what I do or how I mix things around I cannot get all four drives with the Legacy pre-fixes, i.e., P0, P1, P2, and P4.

When I first powered up this box each drive was listed with a Pn pre-fix and a UEFI pre-fix. There were 8 drives listed in each of the four priority lines - one of each category. But once I configured them as desired things changed. If I disconnected and reconnected a drive, sure enough something went amiss. I don't know how to fix it. I've reset the CMOS without success. I've disconnected and rearranged the drives and cables.

I'd love to get a handle on this to figure out how the board is determining whether a connected drive is to be used as a Legacy drive or a UEFI drive, and how do I change that. Essentially, in order to be a boot drive under OS X all the drives must be configured as Legacy drives, not UEFI. Why was this different when the box was first started? Why did it change? I have not made any changes to the BIOS. All the changes recommended in these forums were the board's defaults. The board is a Revision 1.0 with the F11 BIOS.

Thanks for any help.

 

[DBP]

Isn't this affected by the "Hard Drive BBS Priorities" sub-menu a bit further down that screen?
Also because lammergeier only boots into OS X, I set the boot mode to "Legacy only" which removes all the UEFI devices from the boot list (you have to save and come back into the BIOS to see the effect).

 

[skapplin]

Thank you for replying. I tried what you suggested, but the result was that only the two recognized Legacy devices now show up in the Boot Priority list.

For some reason I cannot understand I have two devices that are treated as Legacy devices - the SSD and the optical drive. The two other hard drives are only seen as UEFI devices.

I do have the BBS priorities set correctly.

I am still baffled by this. I do appreciate your suggestions which I just tried. If you have any more ideas I would welcome hearing them.