Will nvidia support multi monitor + SLI on Linux?

Graphics / Linux Linux
1

I was pretty happy with the announcement of new games for Linux and I decided to give it a try.

I’m a power user on linxu and what was my surprise that i found this in my log when I activated SLI:

[ 23021.455] (WW) NVIDIA(0): Multiple display devices requested in MetaMode “DVI-I-0:
[ 23021.455] (WW) NVIDIA(0): nvidia-auto-select @1920x1080 +0+0 {ViewPortIn=1920x1080,
[ 23021.455] (WW) NVIDIA(0): ViewPortOut=1920x1080+0+0}”, but only one allowed when SLI
[ 23021.455] (WW) NVIDIA(0): is enabled; ignoring extra display devices.

But only one allowed when SLI…
But only one allowed when SLI…
But only one allowed when SLI…
But only one allowed when SLI…

This phrase is bouncing now in my heart.

so: Will nvidia support multi monitor + SLI on Linux?

SOLVED

2

Heyyo,

Please go away jwcalla if you’re just going to troll.

I believe what you are looking for NeV3rKilL is SLI mosiac.
ftp://download.nvidia.com/XFree86/Linux-x86_64/334.21/README/sli.html

Please give it a try. Another thing I’ve noticed with SLI in Linux is just using --sli=on doesn’t actually benefit any OpenGL program/game with a preformance boost. Your best bet is to tinker with --sli=afr or --sli=sfr and see which gives you the most beneficial preformance boost.

3

Excellent!

No gain, or almost no gain, but now both GPUs are working and I have more than 1 monitor.

Thank you!

4

I do not know why you think I am trolling when I merely gave an accurate answer.

SLI Mosaic is not supported on GeForce cards. It’s a Quadro-only feature as the documentation you linked clearly states. Nor is TwinView supported in an SLI configuration. This has been discussed many, many times here and on the older forum.

Yes, there is the BaseMosaic option but it’s never been clarified that you’re going to experience SLI performance under that configuration. And I’ve never seen a configuration of SLI + multi-monitor gaming on Linux. If there is one, I am welcome to being corrected.

5

My working config with 2x GTX670 SLI Mosaic enabled and triple monitor

Section "Device"
        Identifier      "Card A"
        Driver          "nvidia"
        BusID           "PCI:1:00:0"
EndSection

Section "Device"
        Identifier      "Card B"
        Driver          "nvidia"
        BusID           "PCI:2:00:0"
EndSection

Section "Monitor"
        Identifier      "Right Monitor"
EndSection

Section "Monitor"
	Identifier	"Central Monitor"
EndSection

Section "Monitor"
        Identifier      "Left Monitor"
EndSection

Section "Screen"
        Identifier      "Right Screen"
        Device          "Card A"
        Monitor         "Right Monitor"
        DefaultDepth    24
        Option          "SLI" "Mosaic"
        Option          "Stereo" "0"
        Option          "BaseMosaic" "True"
        Option          "MetaModes" "DVI-I-0: nvidia-auto-select +1920+0, DVI-D-0: nvidia-auto-select +3840+0, HDMI-0: nvidia-auto-select +0+0"
        SubSection      "Display"
                        Depth           24
        EndSubSection
EndSection

Section "Screen"
        Identifier      "Central Screen"
        Device          "Card A"
        Monitor         "Central Monitor"
        DefaultDepth    24
        Option          "SLI" "Mosaic"
        Option          "Stereo" "0"
        Option          "BaseMosaic" "True"
        Option          "MetaModes" "DVI-I-0: nvidia-auto-select +1920+0, DVI-D-0: nvidia-auto-select +3840+0, HDMI-0: nvidia-auto-select +0+0"
        SubSection      "Display"
                        Depth           24
        EndSubSection
EndSection

Section "Screen"
        Identifier      "Left Screen"
        Device          "Card A"
        Monitor         "Left Monitor"
        DefaultDepth    24
        Option          "SLI" "Mosaic"
        Option          "Stereo" "0"
        Option          "BaseMosaic" "True"
        Option          "MetaModes" "DVI-I-0: nvidia-auto-select +1920+0, DVI-D-0: nvidia-auto-select +3840+0, HDMI-0: nvidia-auto-select +0+0"
        SubSection      "Display"
                        Depth           24
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default"
        Screen 0        "Right Screen" 0 0
        Option          "Xinerama" "0"
EndSection

Just adjust the MetaModes and your number of screen for your config and it’s work like a charm ! :)

With SLI my fps jumped from max 200 to max 480 in CS:GO and no more fps drops on the scoreboard/operation journal and opening cases

But the first card is always at the powermizer level 2 (in Adaptive mode) even on the desktop without any usage :/

Hope it will be useful for someone :)

6

I apologize if it’s not quite on topic, but are there any updates on other SLI modes(not mosaic - just single monitor) support in linux apps/games? Is there a single more or less modern OpenGL app where SLI performance gain is visible/measurable? For example Unigine Heaven OpenGL benchmark doesn’t see the second GPU at all even if “SLI” is “on” in my config. Some ancient OpenGL apps like D3 seem to have performance increase(I get about 320 fps when SLI is enabled in QHD resolution), but GPU load seems to be quite low - they’re not adequate for such a modern GPU as GTX 970 :(