Problem with Enabling SLI configuration on Linux

I have problem with enabling SLI configuration on Linux OS.
Could you give me advice based on the information below?

Software Environment

Distribution: openSUSE Lear 42.3
Linux Kernel: Linux 4.4.76-1-default
Nvidia Drivers: 418.43

Hardware Environment:

Graphic Cards: (Quantity: 2) MSI GAMING X TRIO GeForce RTX 2080TI’s
Motherboard: ASUS ROG RAMPAGE VI OMEGA STCOM
CPU: Intel i9-9920x

/etc/X11/Xorg.conf

nvidia-xconfig: X configuration file generated by nvidia-xconfig

nvidia-xconfig: version 410.104

Section “ServerLayout”
Identifier “Layout0”
Screen 0 “Screen0” 0 0
InputDevice “Keyboard0” “CoreKeyboard”
InputDevice “Mouse0” “CorePointer”
EndSection

Section “Files”
EndSection

Section “InputDevice”

# generated from data in "/etc/sysconfig/mouse"
Identifier     "Mouse0"
Driver         "mouse"
Option         "Protocol" "IMPS/2"
Option         "Device" "/dev/input/mice"
Option         "Emulate3Buttons" "yes"
Option         "ZAxisMapping" "4 5"

EndSection

Section “InputDevice”

# generated from default
Identifier     "Keyboard0"
Driver         "kbd"

EndSection

Section “Monitor”
Identifier “Monitor0”
VendorName “Unknown”
ModelName “Unknown”
HorizSync 28.0 - 33.0
VertRefresh 43.0 - 72.0
Option “DPMS”
EndSection

Section “Device”
Identifier “Device0”
Driver “nvidia”
VendorName “NVIDIA Corporation”
EndSection

Section “Screen”
Identifier “Screen0”
Device “Device0”
Monitor “Monitor0”
DefaultDepth 24
Option “MultiGPU” “On”
Option “SLI” “On”
SubSection “Display”
Depth 24
EndSubSection
EndSection

Error Message (/val/log/Xorg.0.log)

[ 178.613] (II) NVIDIA GLX Module 410.104 Tue Feb 5 23:01:44 CST 2019
[ 181.250] (EE) NVIDIA(GPU-0): Failed to find a valid SLI configuration.
[ 181.250] (EE) NVIDIA(GPU-0): Invalid SLI configuration 1 of 1:
[ 181.250] (EE) NVIDIA(GPU-0): GPUs:
[ 181.250] (EE) NVIDIA(GPU-0): 1) NVIDIA GPU at PCI:23:0:0
[ 181.250] (EE) NVIDIA(GPU-0): 2) NVIDIA GPU at PCI:101:0:0
[ 181.250] (EE) NVIDIA(GPU-0): Errors:
[ 181.250] (EE) NVIDIA(GPU-0): - No video link present
[ 181.250] (WW) NVIDIA(GPU-0): Failed to find a valid SLI configuration for the NVIDIA
[ 181.250] (WW) NVIDIA(GPU-0): graphics device PCI:101:0:0. Please see Chapter 28:
[ 181.250] (WW) NVIDIA(GPU-0): Configuring SLI and Multi-GPU FrameRendering in the README
[ 181.250] (WW) NVIDIA(GPU-0): for troubleshooting suggestions.

nvidia-bug-report.log.gz (1.51 MB)

Please make sure that you disabled IOMMU in bios.
IIRC, SLI with RTX 2080 will only work with nvlink bridges.
Please run nvidia-bug-report.sh as root and attach the resulting .gz file to your post. Hovering the mouse over an existing post of yours will reveal a paperclip icon.
https://devtalk.nvidia.com/default/topic/1043347/announcements/attaching-files-to-forum-topics-posts/

I’m sorry for being late response.
I was upload the report file what you mentioned.
And I couldn’t find IOMMU option in my bios.
also I already installed nvlink bridges and SLI is work very well on Windows 10 except Linux.

On boot, nouveau is loaded and tries to initialize the gpus. Might have some influence on this.

[    2.034666] nouveau 0000:17:00.0: enabling device (0100 -> 0103)
[    2.034711] nouveau 0000:17:00.0: unknown chipset (162000a1)
[    2.034713] nouveau: probe of 0000:17:00.0 failed with error -12
[    2.034745] nouveau 0000:65:00.0: unknown chipset (162000a1)
[    2.034746] nouveau: probe of 0000:65:00.0 failed with error -12

Please blacklist nouveau and run dracut -f afterwards and see if that helps.

Thanks for fast response generix.
Actually, i’m not familiar with Linux. So could you explain how to initialize gpus?

create a file /etc/modprobe.d/blacklist-nouveau.conf containing

blacklist nouveau

afterwards, run
dracut -f
as root. Reboot, then run
dmesg |grep nouveau
Output should be empty.

Hello generix,
I tried it as you said, but it still does not work sli configuration.

linux-nnds:/ # cd etc/modprobe.d/
linux-nnds:/etc/modprobe.d # ll
total 72
-rw-r--r-- 1 root root 3862 May 10  2017 00-system.conf
-rw-r--r-- 1 root root  532 Nov 15  2012 10-unsupported-modules.conf
-rw-r--r-- 1 root root  181 Jun  6  2017 50-alsa.conf
-rw-r--r-- 1 root root 5009 May 10  2017 50-blacklist.conf
-rw-r--r-- 1 root root  128 Oct 13  2017 50-bluetooth.conf
-rw-r--r-- 1 root root   93 Dec 29 02:10 50-cxgb3.conf
-rw-r--r-- 1 root root   93 Dec 29 02:10 50-cxgb4.conf
-rw-r--r-- 1 root root   33 May 10  2017 50-ipw2200.conf
-rw-r--r-- 1 root root   34 May 10  2017 50-iwl3945.conf
-rw-r--r-- 1 root root  551 Dec 29 02:10 50-libmlx4.conf
-rw-r--r-- 1 root root 1004 Dec 29 02:10 50-mlx4.conf
-rw-r--r-- 1 root root   18 May 10  2017 50-prism54.conf
-rw-r--r-- 1 root root   88 Dec 29 02:10 50-truescale.conf
-rw-r--r-- 1 root root    1 Mar  8 14:33 50-yast.conf
-rw-r--r-- 1 root root    0 Mar  8 14:26 50-yast.conf.YaST2save
-rw-r--r-- 1 root root   47 Nov 22  2011 99-local.conf
-rw-r--r-- 1 root root   18 Mar 18 10:29 blacklist-nouveau.conf
-rw-r--r-- 1 root root 2464 Mar 15 18:44 libpsm2-compat.conf
linux-nnds:/etc/modprobe.d # dmesg |grep nouveau
linux-nnds:/etc/modprobe.d #

The error message like below.

[  2072.944] (II) NVIDIA GLX Module  418.43  Tue Feb 19 01:05:57 CST 2019
[  2075.454] (EE) NVIDIA(GPU-0): Failed to find a valid SLI configuration.
[  2075.455] (EE) NVIDIA(GPU-0): Invalid SLI configuration 1 of 1:
[  2075.455] (EE) NVIDIA(GPU-0): GPUs:
[  2075.455] (EE) NVIDIA(GPU-0):     1) NVIDIA GPU at PCI:23:0:0
[  2075.455] (EE) NVIDIA(GPU-0):     2) NVIDIA GPU at PCI:101:0:0
[  2075.455] (EE) NVIDIA(GPU-0): Errors:
[  2075.455] (EE) NVIDIA(GPU-0):     - No video link present
[  2075.455] (WW) NVIDIA(GPU-0): Failed to find a valid SLI configuration for the NVIDIA
[  2075.455] (WW) NVIDIA(GPU-0):     graphics device PCI:101:0:0. Please see Chapter 28:
[  2075.455] (WW) NVIDIA(GPU-0):     Configuring SLI and Multi-GPU FrameRendering in the README
[  2075.455] (WW) NVIDIA(GPU-0):     for troubleshooting suggestions.

What should I do next step?

Could you give me a different solution for this problem?

Please make sure that the nvlink bridge is properly pushed in and the logo on it is lit. Otherwise, you can only send your nvidia-bug-report.log to linux-bugs[at]nvidia.com and hope they’ll come up with something.

If there is a problem with the nvlink bridge, there should be a problem in the Windows OS, but there is no problem in the Windows OS.

Not necessarily. SLI should work without an nvlink bridge but from previous experience, on linux with RTX cards it doesn’t.