AMD Ryzen and CentOS 7 issues

Stability problem

Stock CentOS 7 has an old kernel 3.10.x which is causing major stability issues with AMD Ryzen 7 and the B350 series of motherboards.

Solution

Switch to the newer 4.1x kernel as follows;

Install latest 4.1x kernel from ElRepo

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
yum --enablerepo=elrepo-kernel install -y kernel-ml

Reboot and select the 4.1x option in Grub boot options screen

Regenerate Grub2 config files

grub2-mkconfig -o /boot/grub2/grub.cfg

Change Grub settings

Edit /etc/default/grub
Change GRUB_DEFAULT = saved to 0

Or

List Grub boot options

grep "^menuentry" /boot/grub2/grub.cfg | cut -d "'" -f2

Set default Kernel

grub2-set-default 0
grub2-editenv list

Reboot. Default boot will load the 4.1x kernel.

Verify

uname -r

Disable Kernel Updates

Update: yum installs or updates will revert back to the base kernel version 3.10.x, to stop kernel updates edit /etc/yum.conf and under the [main] section add line

exclude=kernel*

or remember to add the exclude option during yum

yum -x 'kernel*' update