[rodalpho]

Don't ever turn off acpi ... not matter what happens. This will crash / burn your device and if you are unlucky one cpu will be left when run in that mode. modern system don't work without ACPI at all.

Based upon your very strongly worded warning, I removed acpi=off and installed 4.3 mainline, which works fine. Got two CPUs again. Pain in the butt.

Acpi=off seemed to be working fine, temps were not a problem, but you're right in that I only showed 1 CPU active. I added it to the wiki, do you think it should be removed?

For any lurkers, remove acpi=off from /etc/defaults/grub then:

Code:

mkdir /tmp/kern
cd /tmp/kern
wget http://kernel.ubuntu.com/%7Ekernel-ppa/mainline/v4.3-wily/linux-headers-4.3.0-040300_4.3.0-040300.201511020949_all.deb
wget http://kernel.ubuntu.com/%7Ekernel-ppa/mainline/v4.3-wily/linux-headers-4.3.0-040300-generic_4.3.0-040300.201511020949_amd64.deb
wget http://kernel.ubuntu.com/%7Ekernel-ppa/mainline/v4.3-wily/linux-image-4.3.0-040300-generic_4.3.0-040300.201511020949_amd64.deb
dpkg -i *.deb    
update-grub

4.3 isn't technically out yet, so as future releases come out check for the newest file in those URLs. Or just stick with 3.19, which I think is probably the smarter way to go.