Default uses that, the default values embedded by the board manufacturer.
Optimized Defaults uses basic settings designed to get the most out of your installed hardware.
i would always use Optimized
unless troubleshooting odd behavior.
Thanks for your reply, quess I'll be selecting Optimized Defaults before doing the BIOS update. I have the i9-13900k (w/ASUS z690i) running at stock settings, no overclocking, however I do have XMP enabled to get the most out of my ram. I need to do/should do the new BIOS update to curb any possible high Vcore voltages & high temps.
Thus far I haven't had an issue. I'm a content creator/real estate photographer/ & video, so I don't tax my system as someone who games with high cpu usage over long periods of time. At present time my pc is operating within good operational limits, 39C @ idle, 53C under load & want to keep it that way.
Never done a BIOS update before so proceeding with caution, reading articles, ASUS manual, & watching YT how-to-videos. But only a couple times has someone even mentioned resetting to Factory settings before doing a BIOS update so I was wondering if it makes a difference or not to do so & if so which to select? Even the z690i doesn't make any mention of doing it. Hence my post.