Just found this thread to subscribe to it, something I forgot to do almost 13 months ago after my Black Friday bargaintastic purchase!
I updated to the F22C bios months ago, perhaps around Easter, provided by a link from the Gigabyte rep in here (Gigaman?). I don't think I've overclocked the system since then, so I still have no idea if I have the same issue I vaguely recall some of you having regarding the supplied memory.
For a while, I was unable to enter bios over the summer, despite going bonkers on Del and F12. In the end, I shorted the two reset jumper pins with a screwdriver head, which solved that issue.
Every now and again, my system crashed and when I was able to look in bios, I noticed the auto stock core voltage for the 5820k was showing a fraction under 1.0v (which I took to mean there was a little of the very common for years "vdroop"). Despite not consulting the boards, I decided to manually adjust the core voltage by adding literally a click or two above 1.0v and it seems to have helped.
Every now and then, the system boots up from being turned on and my Microsoft Razer Reclusa keyboard will not input my Windows 10 Home password. This is normally solved by powering off, wait ~10 seconds and then power on again.
I've noticed that System Info reports my bios is in Legacy mode, rather than UEFI. Every now and again I ponder either doing a fresh install of Windows 10, or finding that conversion command line entry.
Another thing I sometimes ponder is updating to F22 bios released 14th June 2016, as shown at
http://www.gigabyte.com/products/product-page.aspx?pid=5281&dl=#bios
And finally, can anyone remind what the issue was regarding the xHCI setting in bios, please? I vaguely recall one solution to whatever the problem is/was was to either select "auto" or "smart auto."