I've installed 18.04 and updated the BIOS to 44.
I've tried adding
nomodeset to the end of the linux line.
I've tried kernels 4.17.3 and 4.18-rc3 too. I've tried running off each individual stick of RAM and both together.
It freezes with just the text:
Loading Linux 4.15.0-23-generic Loading initial ramdisk
Annoyingly, the Live CD just runs fine with nomodeset, but the installed version apparently doesn't, although I can chroot it from the live CD, fetch updates, etc fine.