Arch Linux

Bassface

Member

Registered: 2018-09-26

Posts: 2

X220 eGPU issue - Configuration and Reverse PRIME

Hello,
before i've opened this topic i've searched basically half the Internet but couldn't find a good answer to my question.

So i have an Lenovo X220 i5-2520M, on it a Powercolor AMD RX 570  4GB is connected with a PCI-E V8.4D EXP GDC adapter (sometimes called Beast). Installed is the amdgpu open source driver plus radeon-vulkan and of course mesa. An external display is connected to the AMD card which will be the main display.

I wanted the setup such that no data from the card's framebuffer gets sent back to the Intel GPU and therefore reducing the already small bandwith of the PC Card.

right now i'm using reverse PRIME with the external card as the main card and this conf for X, as described in the Arch wiki:

   Section "ServerLayout"
  1     Identifier "layout"
  2        # Screen  "amdgpu"
  3             Inactive "intel"
  4             EndSection
  5
  6             Section "Device"
  7                         Identifier  "AMD"
  8                             Driver      "amdgpu"
  9                                 BusID       "PCI:05:00:00"
10                                 EndSection
11
12                                 Section "Screen"
13                                             Identifier "AMD"
14                                                 Device "amdgpu"
15                                                 EndSection
16
17                                                 Section "Device"
18                                                             Identifier  "intel"
19                                                                 Driver      "intel"
20                                                                     BusID       "PCI:00:02:0" 
21                                                                     EndSection
22
23                                                                     Section "Screen"
24                                                                                 Identifier "intel"
25                                                                                     Device "intel"
26                                                                                     EndSection

Right now it works somewhat, but I think the framebuffer still gets copied back - which results in low framerates in gaming. It's not unusable but i think there should be more in it.

Did i overlook something?

Additional info:
-DRI_PRIME=1 glxinfo | grep "OpenGL renderer" shows my the Intel card.
-glxinfo | grep "OpenGL renderer" shows me the AMD card.

-xrandr --setprovideroffloadsink 1 0 and 0 1 both gives me "BadValue"  errors.
-xrandr shows me all outputs available, from laptop, card and dock, no problems. Even though the Laptop ones shouldnt show up when it's supposedly deactivated, right?
-i can switch on and off LVDS1 without any problems, so it indeed still receives data.

Regards

anotherAlex154

Member

Registered: 2018-10-20

Posts: 10

Re: X220 eGPU issue - Configuration and Reverse PRIME

xrandr --listproviders?

---

"Hey hey hey, everyone part like the Red Sea, it's me" -- Shaggy Rogers

Bassface

Member

Registered: 2018-09-26

Posts: 2

Re: X220 eGPU issue - Configuration and Reverse PRIME

well i'm out and about and the gpu is at home but --listproviders says nothing unusual, lists both GPUs.

right now i simply use modesetting, which seems to work quite well. external screen gets recognized as primary screenafter startx,

Section "Device"
     Identifier "amdgpu"
         Driver "modesetting"
             BusID "PCI:05:00:0"
             EndSection

             Section "Device"
                         Identifier "intel"
                             Driver "modesetting"
                                 BusID "PCI:00:02:0"
                                 EndSection

only issue i have is, that after a while, between 15 minutes and 1 hour, the GPU seems to sh*t itself.  Screen freezes, audio etc. still plays on and i can SSH into it.

  dmesg sometimes says "amdgpu_job_timeout", sometimes says "gpu recovery failed" which i guess is related to it.