How to enable FreeSync on amdgpu?

English Hardware
1

Following the breakage of my previous GPU I decided to buy a more modern graphics card today, just finished installing the newer model which I’m very happy with! The new card supports AMD FreeSync, so does my monitor, and I’m using a DisplayPort cable which I understand is the only connection supported by the kernel for now. Seeing I meet all the criteria, I figured I’d ask what it will take to ensure variable refresh rate is enabled. My new video card is an ASUS Radeon RX 570 ROG STRIX.

Unfortunately the only information I could find is the xrandr --props command, it indeed shows vrr_capable: 1 for my DP connection so that’s a good start. Capable doesn’t mean enabled though, and I couldn’t find the command to actually ensure that it is. When running a game in full screen (eg: TheDarkMod or RedEclipse) the monitor’s OSD still shows a fixed refresh rate, I take it that means not enabled. Is it possible to turn FS on and give it a test, ideally without having to hack system configs and make permanent changes to files maintained by system packages?

2

Hi
You could try the amdgpu module option(s) in grub kernel options;


amdgpu.freesync_video=1

You can see what the current module options are with systool under “Parameters:”


systool -vm amdgpu
3

Thanks! I used the systool -vm amdgpu command, initially it was reporting no freesync, after booting with the amdgpu.freesync_video=1 kernel parameter it now reports freesync_video = "1". I take it this means it should be enabled, though I can’t tell as the monitor’s OSD doesn’t label it… any way to be certain that it’s really working?

4

Hi
See https://www.amd.com/en/support/kb/faq/gpu-754#faq-Enabling/Disabling-AMD-FreeSync

5

I seem to be getting an error when trying that:

**[mircea@linux-qz0r[/b]** ~****]$** DISPLAY=:0 xrandr --output DisplayPort-0 --set "freesync" 1  
X Error of failed request:  BadName (named color or font does not exist) 
  Major opcode of failed request:  140 (RANDR) 
  Minor opcode of failed request:  11 (RRQueryOutputProperty) 
  Serial number of failed request:  43 
  Current serial number in output stream:  43

**

6

Hi
And Adaptive Sync is enabled on the monitor?**

7

The option in the monitor is called AMD Freesync, it’s indeed set to on. I take it something might be wrong with the format of that command, funny it would complain about color codes or fonts of all things.

8

Hi
The only other thing is the display port cable, it is the DisplayPort 1.4 version?

9

I’m not sure on that one. Is there a command to detect and report the DP version of the connection? For cables in particular it’s harder to know and remember the versions, I think I bought it from a local store and it didn’t come with a package or label containing that info.

10

Hi
Not sure, did it say for 8K or 4K 240Hz? May only be 1.2?

11

My monitor is running at 144 Hz 1080p. I was using DisplayPort because due to the model it would only do 120 Hz on HDMI cable. Seems it was a good idea since Freesync apparently requires it, but yeah it seems to be getting stuck on something still.

12

Hi
AFAIK, with the boot option should be enough to enable… are you running Wayland, if not switch to that and test.

13

Hi
So I did a quick check (I’m on X11);


cat .local/share/xorg/Xorg.0.log | grep VariableRefresh

    43.343] (==) AMDGPU(0): VariableRefresh: disabled

So, I edited /usr/share/X11/xorg.conf.d/10-amdgpu.conf and added;


    Option "DRI" "3"
    Option "VariableRefresh" "true"

Then rebooted… and now…


cat .local/share/xorg/Xorg.0.log | grep VariableRefresh

     6.811] (**) AMDGPU(0): Option "VariableRefresh" "true"
     7.640] (**) AMDGPU(0): VariableRefresh: enabled
14

DisplayPort 1.2a supports Freesync: DisplayPort - Wikipedia