It does say "Auto". I'm pretty sure that if it is selected, it runs EFI files, and if it is not selected, it runs legacy MBR.
That said, you probably want GPT to be enabled. See this for more information.
Hmm, in my opinion "auto" runs legacy BIOS if there is no EFI files and configs.
If I remember correctly, I have it set "auto" and it runs non EFI boot.
Yeah, it is a bad company. But the mobo I bought works. And yeah, that's a bad excuse, so I don't even use it as one. But at least they didn't supply me with tons of CDs containing shit software. Only Norton virus thing.
Yea, that's what I meant. Should have been more clear, sorry. By "selected" and "not selected" I meant the "On" and "Off" parameters, not "Auto".
By the way I just tested UEFI/EFI whatever boot with Debian Wheezy beta disk.
1. The boot menu showed an option to boot UEFI from the CD-ROM.
2. I selected UEFI.
3. I clicked through installation of Debian with default settings, noticing that Debian made UEFI boot partition.
4. I rebooted the computer and everything worked (except sounds, but that's another issue).
5. I upgraded the kernel to fix sound issue and to see can Debian upgrade the kernel without messing UEFI.
6. I Rebooted and the sounds worked with the new libre kernel.
Conclusion: For a normal user UEFI can be at the moment with the Gigabyte mobo/BIOS very trivial and simple.