BIOS update worked, settings changed, machine hangs before bios screen

[thewad]

PROJECT: replace i5 6600K with i7 7700K on a UD z170x-ud5 th board, with an EVGA GTX-950 card, previously stable w/El Cap ~1.5 years.

Upgraded my BIOS to F22a from F5 and machine showed the BIOS screen, then the CLOVER screen, then tried to boot OSX only to hang with a few white pixels on the left of the progress bar. I thought, "You idiot" and rebooted and entered BIOS, confirming that it was F22a. Intrigued by the posting "https://www.tonymacx86.com/threads/...bios-f22a-high-sierra-install-success.238494/" I changed the BIOS settings to those shown.

I am regretting this. I didn't worry too much, as the systems were so similar, and if something choked I could always come back to the BIOS setup and make the necessary changes. Upon rebooting, the fans spin, after awhile the RAID 0 HDs start chattering. RAIDs are not boot disks, I disconnected them and reboot. Same behavior except after awhile the internal drive light starts flickering, suggesting the boot SSD is talking. Reboot holding delete key just to see if I can pause the process as if, somewhere, the BIOS was open. No luck.

That's were I am now. Rebooting ends in a hang, typically with error codes A0 (IDE initialization is started) or A6 (Detect and install all connected SCSI drives) and no stop at BIOS, much less CLOVER.

Potentially unorthodox BIOS changes listed below.
M.I.T/Extreme Memory Thread (EXT) profile 1
Peripherals/Initial Display Output IGFX

 

[thewad]

So, based on some more searching around, I tried attaching the monitor not through the video card, but through the HDMI port. Got to the BIOS, and subsequently to CLOVER, deselected InjectNvidia, selected InjectIntel, progress bar for OSX boot makes it 2/3 of the way and screen goes blank. Used BIOS to change Peripherals/Initial Display Output to PCI-1, deselected InjectNvidia (different problem, maybe later thread), switched monitor input to digital and was able to boot to poor graphics mode, but she's alive, SHE'S ALIVE!

Now I just have to build up the emotional capital to pop the i7 7700K in and start hacking at the inevitable audio/video issues.