Slackware Installation Guide
From cchtml.com
If you have poerlbms with a too noisy fan:PutOption "ClockGating" "on"Option "ForceLowPowerMode" "on"in your xorg.conf.But KMS (Kernel Mode Switching) must be disabled, this can be done viaoptions radeon modeset=0in /etc/modprobe.d/radeon-kms.conf