Ok, so I found the following solution. I'm still going to deal with APFS for Mojave, but for now high sierra is perfectly running with HFS+ on my SSD :)
Hello people, I am very proud that I have finally managed a super working High Sierra. Graphics, audio, internet, everything works really well.
I used an old HDD for the test and since everything runs perfectly now I euphorically deleted my SSD to recreate the final High Sierra step by step...
@BreBo, thx and done :)
With space bar I got only the option to "Boot Windows", so I tried Options -> Boot Args and added "-v" at the end.
That seems to work because now I get a ton of Code instead of the apple logo.
This is my setup for the installer:
-New USB Stick: Formated with OS X...
Same here, this is my Hardware:
CPU: i7 6700K
MoBo: Asus Maxmimus Hero VIII (Z170) (latest Bios)
GC: GTX 1080 Ti
I used a Mac mini with High Sierra (latest updates) to create the USB Installer.
I stuck at the Apple logo and the bar won’t even load a bit.