Ända lösningen så långt är att använda ATI opensource drivers. D.v.s installera xf86-video-ati-7.7.0-x86_64-1.txz alternativt xf86-video-amdgpu-1.1.0-x86_64-1.txz beroende på vilket radeon grafikkort du använder i slackware 14.2 eller slackware current.

Konfigurera X att använda korrekt drivrutin och önskade parametrar.

"We are sure you'll enjoy the many improvements.  We've done our best 
to bring the latest technology to Slackware while still maintaining the 
stability and security that you have come to expect.  Slackware is well 
known for its simplicity and the fact that we try to bring software to 
you in the condition that the authors intended.

Slackware 14.2 brings many updates and enhancements, among which 
you'll find two of the most advanced desktop environments available 
today: Xfce 4.12.1, a fast and lightweight but visually appealing and 
easy to use desktop environment, and KDE 4.14.21 (KDE 4.14.3 with
kdelibs-4.14.21) a stable release of the 4.14.x series of the award-
winning KDE desktop environment.  These desktops utilize eudev, udisks,
and udisks2, and many of the specifications from freedesktop.org which
allow the system administrator to grant use of various hardware devices
according to users' group membership so that they will be able to use
items such as USB flash sticks, USB cameras that appear like USB storage,
portable hard drives, CD and DVD media, MP3 players, and more, all
without requiring sudo, the mount or umount command.  Just plug and play.
Slackware's desktop should be suitable for any level of Linux experience.

Slackware uses the 4.4.14 kernel bringing you advanced performance 
features such as journaling filesystems, SCSI and ATA RAID volume 
support, SATA support, Software RAID, LVM (the Logical Volume Manager), 
and encrypted filesystems.  Kernel support for X DRI (the Direct 
Rendering Interface) brings high-speed hardware accelerated 3D graphics 
to Linux.

There are two kinds of kernels in Slackware.  First there are the 
huge kernels, which contain support for just about every driver in the 
Linux kernel. These are primarily intended to be used for installation, 
but there's no real reason that you couldn't continue to run them after 
you have installed.  The other type of kernel is the generic kernel, in 
which nearly every driver is built as a module.  To use a generic kernel 
you'll need to build an initrd to load your filesystem module and 
possibly your drive controller or other drivers needed at boot time, 
configure LILO to load the initrd at boot, and reinstall LILO.  See the 
docs in /boot after installing for more information.  Slackware's Linux 
kernels come in both SMP and non-SMP types now.  The SMP kernel supports 
multiple processors, multi-core CPUs, HyperThreading, and about every 
other optimization available.  In our own testing this kernel has proven 
to be fast, stable, and reliable.  We recommend using the SMP kernel 
even on single processor machines if it will run on them.  Note that on
x86_64 (64-bit), all the kernels are SMP capable."

Mer info via denna länk