- Next Boot: Detect fans added to the motherboard upon next boot only.
- Disabled: Will not detect fans added to the motherboard, new fans may perform erratically.
- Always: Detect fans added to the motherboard (may cause a slight delay and increased noise during startup).
See "BIOS Beep Codes" in the Quick Reference section of Webopedia.
Also see "The System Boot Process Explained" in Webopedia’s Did You Know…? section.