Catalyst 15.7 for Linux must supports AMD Radeon R9 Fury X as described in "Supported Products list"
If you install fglrx (Catalyst package), yes - you'll have support.
I tried it by patching the modules required for DKMS and it booted to black screen.
I could downgrade to an earlier kernel but I honestly don't want to mess with that again for a while.
Currently I use Debian 8 (Jessie, kernel 13.16) and Radeon HD5850 with Catalyst 15.7 (fglrx-driver) directly installed from "unstable" branch. Unfortunately I can't advice how to install ubuntu kernel or fglrx-driver despite of ubuntu very similar to debian.
Figured out a solution without fglrx to get the Fury X working!
1) Follow steps in (1) to install kernel building prerequisites
2) Find the mainline build in (4) that you want to use as the base. I did today's (2015-08-14) daily since I was already on 4.2.0_rc4.
3) Follow the steps in (1) to pull the source from repo. Since I used the latest daily, avoided having to checkout to a specific commit.
4) Download the patch files for the mainline build you will compile. Should be 3 of them.
5) In a separate subdirectory, git clone git://people.freedesktop.org/~agd5f/linux -b drm-next-4.3-wip amdgpu
6) Follow steps in (1) to apply Debian/Ubuntu patches to mainline kernel. This makes it ready to build for you, but we still need the amdgpu changes.
7) In the mainline kernel, rm -rf drivers/gpu/drm/amd and rm -rf drivers/gpu/drm/radeon. We need the new versions.
8) Go into amdgpu subdir after cloned, and inside go to drivers/gpu/drm. Copy recursively (I did cp -rp) amd and radeon subdirs to mainline's drivers/gpu/drm.
You should be able to go back in there and see the amd and radeon subdirs now.
9) Use (2)'s "Kernel Build and Installation" to pull the config and make the kernel. This built for me without errors.
10) Install the packages. I had 3 - headers, image and firmware_image.
11) Reboot to new kernel. The "About this Computer" still shows Gallium 0.4 on llvmpipe (LLVM 3.6, 256 bits), but it's usable again.
I'll try to see if I can get fglrx to install now that I got this far, but will have to be another day.
1) Fury X is usable with just amdgpu but seems not fully since firmware is missing. Will have to wait until AMD commits that.
(Sent an e-mail to committer of change to inquire.)
2) Starting with Ubuntu 15.10 sources the installer for fglrx has been patched up to 4.2 kernels and does work from sudo apt-get install fglrx.
Fury X now showing properly, only possible concern is that firmware error mentioned above.
Hoping that gets backported to older repos here soon.
+1 about proprietary drivers.
The description of my problem is in Intel / ATI PowerXpress & fglrx topic. My discrete AMD GPU has never worked with fglrx (I bought this laptop ~1.5 years ago).
radeon driver works, but I need fglrx driver.
What version of Linux are you using?
I've gotten 15.4 to work on up to a 3.19 kernel and Ubuntu 15.04
Just stopped messing with it because I'm not gaming on that side.
> lsb_release -idrc && echo Kernel Release: `uname -r`
Distributor ID: openSUSE project
Description: openSUSE 13.2 (Harlequin) (x86_64)
Kernel Release: 3.16.7-21-desktop
Tried also openSUSE 11.4 -- 13.1, Ubuntu 12.04, 14.04, Fedora 21, Debian 8 Jessie -- the same result with all versions of fglrx (starting from 13.8-th; previous versions don't support my card).