American Megatrends MAN-758 manual Default, Original, Optimal, Fail-Safe

Section 4 Default

The icons in this section permit you to select a group of settings for all WINBIOS Setup options. Not only can you use these icons to quickly set system configuration parameters, you can choose a group of settings that have a better chance of working when the system is having configuration-related problems.

Original	Choose the Original icon to return to the system configuration values present
	in WINBIOS Setup when you first began this WINBIOS Setup session.
Optimal	You can load the optimal default settings for the WINBIOS by selecting the
	Optimal icon. The Optimal default settings are best-case values that should
	optimize system performance. If NVRAM is corrupted, the Optimal settings are
	loaded automatically.
Fail-Safe	You can load the Fail-Safe WINBIOS Setup option settings by selecting the
	Fail-Safe icon from the Default section of the WINBIOS Setup main menu.
	The Fail-Safe settings provide far from optimal system performance, but are the
	most stable settings. Use this option as a diagnostic aid if the system is
	behaving erratically.

78MegaRUM PCI Motherboard User’s Guide