Radeon VII and Ubuntu problems

I'm currently running a Radeon VII on ubuntu 18.04.
Using kernel 4.15.0-47-generic and amdgpu-pro-18.50-725072.
Try this:
Install kernel 4.15.0-47-generic

sudo apt-get install 
linux-image-4.15.0-47-generic 
linux-modules-4.15.0-47-generic
linux-modules-extra-4.15.0-47-generic 
linux-headers-4.15.0-47-generic
sudo update-grub

Then download amdgpu-pro 18.50 from http://amd.com

wget --referer support.amd.com 
https://drivers.amd.com/drivers/linux/amdgpu-pro-18.50-725072-ubuntu-18.04.tar.xz 
tar xf amdgpu-pro-18.50-725072-ubuntu-18.04.tar.xz
cd amdgpu-pro-18.50-725072-ubuntu-18.04
./amdgpu-pro-install

Add amdgpu.dc=1 to GRUB_CMDLINE_LINUX in /etc/default/grub run sudo update-grub and reboot into kernel 4.15.0-47-generic.

And Voilà
Cheers

Update.

I found these instructions. The author deals with an RX590, but the process is almost identical.

Youtube: https://www.youtube.com/watch?v=qK5ra2eed7w Written version: https://forum.level1techs.com/t/rx590-ubuntu-18-04-setup-guide/137521

Here’s what I ended up doing.

Install UKUU, (ubuntu kernel update utility) which makes kernel installation really easy. https://www.omgubuntu.co.uk/2017/02/ukuu-easy-way-to-install-mainline-kernel-ubuntu

Using UKUU, Install kernel 4.20 or later. (I used 5.0.2)

Caution: If you reboot at this point, the new kernel will give you a black screen when you try to log in. To get around that you need to temporarily add the kernel boot parameter 'nomodeset' into grub. To do that, you press 'e' when the boot options come up. That puts you into grub's edit mode. Add ‘nomodeset’ right after the ‘quiet’ or ‘splash’ term. Press F10 to exit and continue booting. How do I add a kernel boot parameter?

Download the Radeon VII Vega 20 firmware blobs. https://people.freedesktop.org/~agd5f/radeon_ucode/vg20/

Put the firmware files in the /lib/firmware/amdgpu folder.

Update initramfs. 'sudo update-initramfs -k all -u'

Reboot. You shouldn’t need ‘nomodeset’ to get back in at this point.

Check to see what firmware has been loaded. 'dmesg |grep firmware' or ‘dmesg |grep vega’ or ‘dmesg |grep amdgpu’

I got an error message “Direct firmware load for amdgpu/vega20_ta.bin failed with error -2". But there is no such file on the firmware download site. It will probably be fixed later.

This allows me to run a large (150 mods) Minecraft modpack at 30+FPS, instead of 1 fps. That's at moderate graphic setting. The performance is about the same in Win 10. OpenGL is still at 18.2.2. I have not updated via Padoka or Obaif.

I got the same results, and posted a very similar question. AMDGPU Pro drivers from AMD didn't help. VGA20 files in lib/firmware/amdgpu didn't help. Padoka PPA didn't help. Kernels 4.20 and 5.0 didn't help.

But I made some headway with Dual boot. I got them to install and coexist (on two separate SSDs) by re-installing both Win 10 and Kubuntu 18.04 in BIOS mode. To do that, I had to use RUFUS (in windows) to burn the install images to the USB drives. Rufus has an option to create a hybrid bios/Uefi drive. Then when booting it, you need to press F12 (or whatever your mobo requires) to select the BIOS version of the drive.

Since then, I flashed the Radeon vbios to 106 and checked to see if it fixed anything. No cigar.

I think it's a UEFI firmware issue.