Question Gigabyte 970A-DS3P boot devices priority settings

[ProzacR]

Hi I just added my old SSD to my new motherboard Gigabyte 970A-DS3P besides another SSD that came together and it boots my main windows 10 system.
I think I even set up something to boot from both drives, but for some reason my old SSD is not visible in boot selection menu.
Any ideas how to get it working that way? Some BIOS settings?
I tired all those legacy things but not sure.
And without doing anything it is still wisable in main OS as my drive D: and working fine in that way. So it is not broken at all.

 

[Lutfij]

The SSD that was on the build to begin with has the OS on it? If so, what OS are you working with on your platform, for both drives?

I think I even set up something to boot from both drives
What did you install?

Just curious, why would you want to (dual)boot off of two OSes?