Manjaro, Kubuntu 20.10 and Ubuntu 20.04.1 LTS all crash on me if I won't set maxcpus=1 in GRUB. Replacing quiet splash with nomodeset or changing UEFI BIOS settings to disable all Intel CPU features changes nothing.

Windows 10 runs without issues and is perfectly stable.

Available crash logs:

mce: [Hardware Error]: CPU 5: Machine Check Exception: 5 Bank 0: f600020000040150

mce: [Hardware Error]: RIP !INEXACT! 10:<fffffffffb9c7e8eb> {mwait_idle_with_hints.constprop.0+0x4b/0x90}

mce: [Hardware Error]: TSC 25d1e1e46d ADDR 7fabd0e68be3

mce: [Hardware Error]: PROCESSOR 0:506e3 TIME 1605392958 SOCKET 0 APIC 3 microcode dcd64.deb: mismatch OK4.deb

mce: [Hardware Error]: Run the above through 'mcelog --ascii'

mce: [Hardware Error]: CPU 1: Machine Check Exception: 5 Bank 0: f60001c000040150

mce: [Hardware Error]: RIP !INEXACT! 33:<0007fadb0e68bea>

mce: [Hardware Error]: TSC 25d1e1dc9 ADDR 1605392958

mce: [Hardware Error]: PROCESSOR 0:506e3 TIME 1605392958 SOCKET 0 APIC 2 microcode dc

mce: [Hardware Error]: Run the above through 'mcelog --ascii'

mce: [Hardware Error]: Machine check: Processor context corrupt

Kernel panic - not syncing: Fatal machine check

Kernel Offset: 0x38600000 from 0xfffffffff81000000 (relocation range: 0xfffffffff8000000-0xffffffffbffffff)

Rebooting in 30 seconds..

CPU: i7-6700K

GPU: GTX-1070

Motherboard: ASUS Z170-P

UEFI BIOS: 3805 x64 05/16/2018 (latest at the time of writting)

ME Firmware Version: 11.8.55.3510 (latest at the time of writting)

I'd like to know if it would be possible to use more than 1/8 vCPU (4 physical cores x 2 virtual cores each).