[SOLVED] NVIDIA SLI for 1080's

[Rubus]

Hello.

I found this thread about enabling SLI on NVIDIA cards (viewtopic.php?t=215078), and I have two NVIDIA 1080's in SLI, but following the instructions on the previously mentioned thread doesn't work for me.

When I do this: 2. Setting up SLI
- begin by getting everything closed out, so your DE is running.
- open your terminal, and enter
CODE: SELECT ALL

sudo nvidia-xconfig --sli=On

I receive a message that says, "Invalid SLI option: On. Invalid commandline, please run `nvidia-xconfig --help` for usage information."

No second/new xorg. conf file is created.

When I find and open the xorg.conf file, all I see is:
Section "Device"
Identifier "Intel"
Driver "intel"
# Option "AccelMethod" "uxa"
EndSection

Does anyone have any idea what I'm possibly doing wrong? I would certainly like to enable SLI if I can. Thank you.

[Hoser Rob]

No nvidia expert here but that HowTo is from 2016. You can't expect old solutions to work in newer Linux releases, there isn't much backwards compatibility in Linux in general.

[SMG]

No second/new xorg. conf file is created.

Linux Mint does not normally create an xorg.conf file so the fact you have one and the fact it mentions Intel means you should provide system information in order for others to properly help you.

Please open the System Reports app and click the System Information tab on the left. Your computer's information should come up in the right pane. Then click the Copy button in the lower right and paste the results into a reply window here so we can see how Linux Mint views your hardware.

[Rubus]

Thank you for those specific instructions, because to be honest, I don't know what I'm doing.

Below is what came up in System Reports, and thank you in advance for helping a relatively newbie to Linux, but also definitely NOT a super techie.

Code: Select all

System:
  Kernel: 5.15.0-67-generic x86_64 bits: 64 compiler: gcc v: 11.3.0 Desktop: Cinnamon 5.6.8
    tk: GTK 3.24.33 wm: muffin dm: LightDM Distro: Linux Mint 21.1 Vera base: Ubuntu 22.04 jammy
Machine:
  Type: Desktop System: Gigabyte product: N/A v: N/A serial: <superuser required>
  Mobo: Gigabyte model: X99-Designare EX-CF serial: <superuser required>
    UEFI-[Legacy]: American Megatrends v: F5c date: 06/15/2018
Battery:
  Device-1: hidpp_battery_0 model: Logitech M570 serial: <filter> charge: 60% status: Discharging
CPU:
  Info: 6-core model: Intel Core i7-6850K bits: 64 type: MT MCP arch: Broadwell rev: 1 cache:
    L1: 384 KiB L2: 1.5 MiB L3: 15 MiB
  Speed (MHz): avg: 1528 high: 3003 min/max: 1200/3600 cores: 1: 1200 2: 3000 3: 1200 4: 1200
    5: 1200 6: 1200 7: 1206 8: 3003 9: 1205 10: 1533 11: 1200 12: 1200 bogomips: 86396
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: NVIDIA GP104 [GeForce GTX 1080] vendor: Gigabyte driver: nvidia v: 525.85.05 pcie:
    speed: 2.5 GT/s lanes: 8 ports: active: none empty: DP-1, DVI-D-1, HDMI-A-1, HDMI-A-2, HDMI-A-3
    bus-ID: 07:00.0 chip-ID: 10de:1b80
  Device-2: NVIDIA GP104 [GeForce GTX 1080] vendor: Gigabyte driver: nvidia v: 525.85.05 pcie:
    speed: 8 GT/s lanes: 16 ports: active: none off: DP-2
    empty: DVI-D-2, HDMI-A-4, HDMI-A-5, HDMI-A-6 bus-ID: 09:00.0 chip-ID: 10de:1b80
  Display: x11 server: X.Org v: 1.21.1.3 driver: X: loaded: nvidia
    unloaded: fbdev,modesetting,nouveau,vesa gpu: nvidia,nvidia display-ID: :0 screens: 1
  Screen-1: 0 s-res: 5504x2304 s-dpi: 120
  Monitor-1: DP-0 res: 5504x2304 dpi: 175 diag: 865mm (34.1")
  OpenGL: renderer: NVIDIA GeForce GTX 1080/PCIe/SSE2 v: 4.6.0 NVIDIA 525.85.05
    direct render: Yes
Audio:
  Device-1: Intel C610/X99 series HD Audio vendor: Gigabyte driver: snd_hda_intel v: kernel
    bus-ID: 00:1b.0 chip-ID: 8086:8d20
  Device-2: NVIDIA GP104 High Definition Audio vendor: Gigabyte driver: snd_hda_intel v: kernel
    pcie: speed: 2.5 GT/s lanes: 8 bus-ID: 07:00.1 chip-ID: 10de:10f0
  Device-3: NVIDIA GP104 High Definition Audio vendor: Gigabyte driver: snd_hda_intel v: kernel
    pcie: speed: 8 GT/s lanes: 16 bus-ID: 09:00.1 chip-ID: 10de:10f0
  Sound Server-1: ALSA v: k5.15.0-67-generic running: yes
  Sound Server-2: PulseAudio v: 15.99.1 running: yes
  Sound Server-3: PipeWire v: 0.3.48 running: yes
Network:
  Device-1: Intel Ethernet I218-V vendor: Gigabyte driver: e1000e v: kernel port: f000
    bus-ID: 00:19.0 chip-ID: 8086:15a1
  IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <filter>
  Device-2: Intel I211 Gigabit Network vendor: Gigabyte driver: igb v: kernel pcie:
    speed: 2.5 GT/s lanes: 1 port: c000 bus-ID: 0b:00.0 chip-ID: 8086:1539
  IF: enp11s0 state: down mac: <filter>
  Device-3: Intel Wireless 8260 driver: iwlwifi v: kernel pcie: speed: 2.5 GT/s lanes: 1
    bus-ID: 0c:00.0 chip-ID: 8086:24f3
  IF: wlp12s0 state: down mac: <filter>
  IF-ID-1: vmnet1 state: unknown speed: N/A duplex: N/A mac: <filter>
  IF-ID-2: vmnet8 state: unknown speed: N/A duplex: N/A mac: <filter>
Bluetooth:
  Device-1: Intel Bluetooth wireless interface type: USB driver: btusb v: 0.8 bus-ID: 3-3:3
    chip-ID: 8087:0a2b
  Report: hciconfig ID: hci0 rfk-id: 0 state: down bt-service: enabled,running rfk-block:
    hardware: no software: yes address: <filter>
Drives:
  Local Storage: total: 9.55 TiB used: 5.16 TiB (54.1%)
  ID-1: /dev/nvme0n1 vendor: Intel model: SSDPE2MW012T4 size: 1.09 TiB speed: 31.6 Gb/s lanes: 4
    serial: <filter> temp: 22.9 C
  ID-2: /dev/nvme1n1 vendor: Samsung model: SSD 960 EVO 1TB size: 931.51 GiB speed: 31.6 Gb/s
    lanes: 4 serial: <filter> temp: 34.9 C
  ID-3: /dev/nvme2n1 vendor: Intel model: SSDPE2MW012T4 size: 1.09 TiB speed: 31.6 Gb/s lanes: 4
    serial: <filter> temp: 22.9 C
  ID-4: /dev/sda vendor: Crucial model: CT2050MX300SSD1 size: 1.86 TiB speed: 6.0 Gb/s
    serial: <filter>
  ID-5: /dev/sdb vendor: Crucial model: CT2050MX300SSD1 size: 1.86 TiB speed: 6.0 Gb/s
    serial: <filter>
  ID-6: /dev/sdc type: USB vendor: Toshiba model: External USB 3.0 size: 2.73 TiB
    serial: <filter>
Partition:
  ID-1: / size: 85.48 GiB used: 44.59 GiB (52.2%) fs: btrfs dev: /dev/nvme1n1p3
  ID-2: /boot/efi size: 487 MiB used: 6.1 MiB (1.2%) fs: vfat dev: /dev/nvme1n1p2
  ID-3: /home size: 845.55 GiB used: 143.04 GiB (16.9%) fs: btrfs dev: /dev/nvme1n1p4
Swap:
  Alert: No swap data was found.
USB:
  Hub-1: 1-0:1 info: Full speed or root hub ports: 2 rev: 2.0 speed: 480 Mb/s chip-ID: 1d6b:0002
  Hub-2: 1-1:2 info: Intel Hub ports: 6 rev: 2.0 speed: 480 Mb/s chip-ID: 8087:800a
  Hub-3: 2-0:1 info: Full speed or root hub ports: 2 rev: 2.0 speed: 480 Mb/s chip-ID: 1d6b:0002
  Hub-4: 2-1:2 info: Intel 8 channel internal hub ports: 8 rev: 2.0 speed: 480 Mb/s
    chip-ID: 8087:8002
  Hub-5: 3-0:1 info: Hi-speed hub with single TT ports: 15 rev: 2.0 speed: 480 Mb/s
    chip-ID: 1d6b:0002
  Hub-6: 3-1:2 info: VIA Labs Hub ports: 4 rev: 2.1 speed: 480 Mb/s chip-ID: 2109:2811
  Device-1: 3-3:3 info: Intel Bluetooth wireless interface type: Bluetooth driver: btusb
    rev: 2.0 speed: 12 Mb/s chip-ID: 8087:0a2b
  Device-2: 3-6:4 info: NZXT Kraken X type: HID driver: nzxt-kraken2,usbhid rev: 2.0
    speed: 12 Mb/s chip-ID: 1e71:170e
  Hub-7: 3-9:5 info: Hitachi ports: 4 rev: 2.1 speed: 480 Mb/s chip-ID: 045b:0209
  Hub-8: 3-10:6 info: Hitachi ports: 4 rev: 2.1 speed: 480 Mb/s chip-ID: 045b:0209
  Device-1: 3-10.4:8 info: Holtek Keyboard LKS02 type: Keyboard,HID driver: hid-generic,usbhid
    rev: 1.1 speed: 1.5 Mb/s chip-ID: 04d9:1702
  Device-2: 3-13:7 info: Corsair Commander PRO type: HID driver: corsair-cpro,usbhid rev: 2.0
    speed: 12 Mb/s chip-ID: 1b1c:0c10
  Hub-9: 3-14:9 info: Genesys Logic Hub ports: 4 rev: 2.0 speed: 480 Mb/s chip-ID: 05e3:0610
  Device-1: 3-14.1:10 info: Logitech Unifying Receiver type: Keyboard,Mouse,HID
    driver: logitech-djreceiver,usbhid rev: 2.0 speed: 12 Mb/s chip-ID: 046d:c52b
  Hub-10: 4-0:1 info: Super-speed hub ports: 6 rev: 3.0 speed: 5 Gb/s chip-ID: 1d6b:0003
  Hub-11: 4-1:2 info: VIA Labs Hub ports: 4 rev: 3.0 speed: 5 Gb/s chip-ID: 2109:8110
  Device-1: 4-1.2:7 info: Toshiba America External Disk 3TB type: Mass Storage
    driver: usb-storage rev: 3.0 speed: 5 Gb/s chip-ID: 0480:d010
  Hub-12: 4-5:3 info: Hitachi ports: 4 rev: 3.0 speed: 5 Gb/s chip-ID: 045b:0210
  Hub-13: 4-6:6 info: Hitachi ports: 4 rev: 3.0 speed: 5 Gb/s chip-ID: 045b:0210
Sensors:
  System Temperatures: cpu: 22.6 C mobo: 20.1 C gpu: nvidia temp: 27 C
  Fan Speeds (RPM): cpu: 953 fan-1: 0 fan-3: 1507 fan-4: 1498 fan-5: 1496 fan-6: 1509
    gpu: nvidia fan: 24%
Repos:
  Packages: 2424 apt: 2384 flatpak: 33 snap: 7
  No active apt repos in: /etc/apt/sources.list
  Active apt repos in: /etc/apt/sources.list.d/microsoft-edge.list
    1: deb [arch=amd64] https: //packages.microsoft.com/repos/edge/ stable main
  Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list
    1: deb http: //packages.linuxmint.com vera main upstream import backport
    2: deb http: //archive.ubuntu.com/ubuntu jammy main restricted universe multiverse
    3: deb http: //archive.ubuntu.com/ubuntu jammy-updates main restricted universe multiverse
    4: deb http: //archive.ubuntu.com/ubuntu jammy-backports main restricted universe multiverse
    5: deb http: //security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
  Active apt repos in: /etc/apt/sources.list.d/steam.list
    1: deb [arch=amd64,i386] https: //repo.steampowered.com/steam/ stable steam
    2: deb-src [arch=amd64,i386] https: //repo.steampowered.com/steam/ stable steam
  Active apt repos in: /etc/apt/sources.list.d/teamviewer.list
    1: deb [signed-by=/usr/share/keyrings/teamviewer-keyring.gpg] https: //linux.teamviewer.com/deb stable main
Info:
  Processes: 455 Uptime: 28m Memory: 125.65 GiB used: 3.24 GiB (2.6%) Init: systemd v: 249
  runlevel: 5 Compilers: gcc: 11.3.0 alt: 11/12 Client: Unknown python3.10 client inxi: 3.3.13

[SMG]

No second/new xorg. conf file is created.

When I find and open the xorg.conf file, all I see is:
Section "Device"
Identifier "Intel"
Driver "intel"
# Option "AccelMethod" "uxa"
EndSection

Do you have any idea how this file ended up on your system? If you run

Code: Select all

cat /etc/X11/xorg.conf

in a terminal, is that what comes out? The fact you have that file may indicate there are other oddities on your system.

Did you use Driver Manager to install the Nvidia drivers on your system?

Is there a specific game/program for which you want to use SLI? I'm asking because the quick searches I have done indicate it's not really useful, but maybe you found information indicating otherwise.

I'm guessing the tutorial you used was based on Nvidia information at the time of the tutorial. Current information is in Chapter 31. Configuring SLI and Multi-GPU Mosaic of the Nvidia 525.85.05 ReadMe. Taking a quick look at it in comparison to older driver Readmes, I do see some differences. There's no listing of nvidia-xconfig --sli=on. It says to go to an appendix. I will look at it more tomorrow when my eyelids are not falling down.

[Rubus]

This is what I got when I did what you mentioned to do in a terminal window.

cat: /etc/X11/xorg.conf: No such file or directory

I'm pretty sure I used Driver Manager to install the video driver, but I have noticed Update Manager seems to have NVIDIA updates quite often - sometimes every day or two.

The only reason I started wondering about the SLI bit is because I installed the Alan Wake remaster, and when I first ran it, it was working great at the highest quality settings. The next time I started it up it was choppy like crazy, and I had to drop the quality settings down quite a bit. I don't know why it was fine at the highest settings the first time, and then the second time I had to drop down the quality settings to make it even usable. I am pretty sure in-between the first and second run of the game there was one of the many NVIDIA updates that came through Update Manager. A friend suggested I look into seeing if SLI was possibly enabled for the first time I ran it, and after the NVIDIA update it was turned off. That's when and why I started looking into this.

Thank you in advance for your looking into this and helping me out. I sincerely appreciate it since I don't really know what I'm doing.

[SMG]

This is what I got when I did what you mentioned to do in a terminal window.

cat: /etc/X11/xorg.conf: No such file or directory

That is the result I would expect to be. The file does not normally exist.

I'm pretty sure I used Driver Manager to install the video driver, but I have noticed Update Manager seems to have NVIDIA updates quite often - sometimes every day or two.

Those are updates for your flatpak programs. That is separate from an Nvidia driver update for your operating system. Flatpaks run separately and have their own components separate from the Driver Manager driver.

The only reason I started wondering about the SLI bit is because I installed the Alan Wake remaster, and when I first ran it, it was working great at the highest quality settings.

I am not familiar with this program to know how one installs it. Did you install it through Steam or use a flatpak version or something else? I just did a quick search and all I saw were xbox versions so I may not have found the correct game.

A friend suggested I look into seeing if SLI was possibly enabled for the first time I ran it, and after the NVIDIA update it was turned off.

If you did not explicitly set up SLI before installing the Alan Wake remaster, then, no, you were not using it.

[Rubus]

I checked in Driver Manager, and it shows I'm using the most current, recommended driver - version 525.89.02.

Alan Wake Remastered is a PC game through the Epic Games Store. I'll do the best I can to explain, but I don't always know what I'm talking about, so hopefully this will make sense.

I have Lutris installed so I can have all my games list up in on program, and then in Lutris I have Steam installed. I had to install the Epic Games Store as a non-Steam program, or else it wouldn't work. So I launch the Epic Games Store through Steam, and when EGS comes up it shows Alan Wake Remastered, and I can launch it from there.

I did some messing around tonight after watching this video with "closed captions" turned on. https://www.youtube.com/watch?v=unlUGL9LyIQ

I opened the NVIDIA X Server Settings, and on the "X Server Display Configuration" section I clicked on the "Save to X Configuration File" button. Then I was able to find the /etc/X11/xorg.conf file. Then following the instructions in "Chapter 31. Configuring SLI and Multi-GPU Mosaic" I enabled SLI with this command: nvidia-xconfig --sli=mosaic

I then followed some of the troubleshooting suggestions at the end of "Chapter 31..." to see if multiple GPU's were identified by the OS and got this:

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dk@FortKnox:~$ lspci | grep -i nvidia
07:00.0 VGA compatible controller: NVIDIA Corporation GP104 [GeForce GTX 1080] (rev a1)
07:00.1 Audio device: NVIDIA Corporation GP104 High Definition Audio Controller (rev a1)
09:00.0 VGA compatible controller: NVIDIA Corporation GP104 [GeForce GTX 1080] (rev a1)
09:00.1 Audio device: NVIDIA Corporation GP104 High Definition Audio Controller (rev a1)

Then I verified that each GPU is connected to a bus connected to the Root Bridge:

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kdk@FortKnox:~$ lspci -t
-+-[0000:ff]-+-0b.0
 |           +-0b.1
 |           +-0b.2
 |           +-0b.3
 |           +-0c.0
 |           +-0c.1
 |           +-0c.2
 |           +-0c.3
 |           +-0c.4
 |           +-0c.5
 |           +-0f.0
 |           +-0f.1
 |           +-0f.4
 |           +-0f.5
 |           +-0f.6
 |           +-10.0
 |           +-10.1
 |           +-10.5
 |           +-10.6
 |           +-10.7
 |           +-12.0
 |           +-12.1
 |           +-13.0
 |           +-13.1
 |           +-13.2
 |           +-13.3
 |           +-13.4
 |           +-13.5
 |           +-13.6
 |           +-13.7
 |           +-14.0
 |           +-14.1
 |           +-14.2
 |           +-14.3
 |           +-14.4
 |           +-14.5
 |           +-14.6
 |           +-14.7
 |           +-15.0
 |           +-15.1
 |           +-15.2
 |           +-15.3
 |           +-16.0
 |           +-16.6
 |           +-16.7
 |           +-17.0
 |           +-17.4
 |           +-17.5
 |           +-17.6
 |           +-17.7
 |           +-1e.0
 |           +-1e.1
 |           +-1e.2
 |           +-1e.3
 |           +-1e.4
 |           +-1f.0
 |           \-1f.2
 \-[0000:00]-+-00.0
             +-01.0-[01]----00.0
             +-01.1-[02]--
             +-02.0-[03-08]----00.0-[04-08]--+-08.0-[05]----00.0
             |                               +-09.0-[06]--
             |                               +-10.0-[07]--+-00.0
             |                               |            \-00.1
             |                               \-11.0-[08]----00.0
             +-03.0-[09]--+-00.0
             |            \-00.1
             +-05.0
             +-05.1
             +-05.2
             +-11.0
             +-11.4
             +-14.0
             +-16.0
             +-19.0
             +-1a.0
             +-1b.0
             +-1c.0-[0a]--
             +-1c.5-[0b]----00.0
             +-1c.7-[0c]----00.0
             +-1d.0
             +-1f.0
             \-1f.3

Trying to not exposed just how dumb I am about all of this, I'm not sure how to tell if SLI is on and working. I did not see anything in the NVIDIA X Server Settings that mentioned SLI.

Also like you mentioned, I don't know if SLI will actually help or not. After watching that video I linked to, it looks to me like the guy ran a bunch of tests and different games and SLI wasn't very helpful, and in some instances made things worse.

So I don't know if I'm wasting my time and yours with this, but it was a nice learning experience for me trying to see how some of this stuff works. Thank you for your time and assistance, and what do you think - is all this worth it, and did I follow the instructions correctly?

[SMG]

The way I read the Nvidia documentation, running the nvidia-xconfig --sli=mosaic command should have set up xorg.conf with the proper settings. However, I also see mention of multiple monitors (which you do not have) with regards to those settings. I don't know if the setting has changed from what it was in the past and maybe it is now more appropriate for a multi-monitor situation.

What is the output of

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cat /etc/X11/xorg.conf

Please enclose the results in code tags as described in this tutorial Displaying terminal output in a post.

I don't normally see people asking about SLI so I don't know much about it.

[ThaCrip]

Alan Wake Remastered is a PC game through the Epic Games Store. I'll do the best I can to explain, but I don't always know what I'm talking about, so hopefully this will make sense.

I have Lutris installed so I can have all my games list up in on program, and then in Lutris I have Steam installed. I had to install the Epic Games Store as a non-Steam program, or else it wouldn't work. So I launch the Epic Games Store through Steam, and when EGS comes up it shows Alan Wake Remastered, and I can launch it from there.

Also like you mentioned, I don't know if SLI will actually help or not. After watching that video I linked to, it looks to me like the guy ran a bunch of tests and different games and SLI wasn't very helpful, and in some instances made things worse.

So I don't know if I'm wasting my time and yours with this, but it was a nice learning experience for me trying to see how some of this stuff works. Thank you for your time and assistance, and what do you think - is all this worth it, and did I follow the instructions correctly?

I would not expect a NVIDIA 1080 GPU running SLI would have any real world benefit on that game given that game's 'recommended requirements' say 'NVIDIA Geforce GTX 1060 6GB' and you are a fair amount beyond that even with ONE 1080 GPU. so in terms of real world performance, even if say two 1080 GPU's running SLI gave you roughly double the performance, it likely won't matter in real world benefit. because once a person hits 60fps+, gains beyond this point tend to drop off dramatically in terms of real world benefit where it really matters.

I got a 1050 Ti 4GB GPU and even a 1060 (especially 6GB VRAM model) is noticeably better than mine and you are pretty much a couple of steps beyond that.

but I guess the learning experience of trying to get SLI working would be nice. but then again I never plan on using SLI as it seems like more trouble than it's worth, especially given you can generally use one GPU with more than good enough performance. off the top of my head, about the only time 1080 GPU's running SLI might help is on the more demanding games, especially if one of those can't maintain 60fps+ etc.

p.s. because I always use the following as a general rule when it comes to frame rate... 30fps is playable, 60fps is basically perfect. that's been true for decades now (I realize some might say 120Hz with 120fps (or the like) can help, but even if true, it's benefits would be FAR less than the 30/60fps rule which is where things are most obvious/beneficial). even on the low end of frame rate for a playable game I would avoid any lower then mid-to-high 20's as in the low 20's (or lower) for any length of time that will become a big problem and quickly. but a brief dip into the low 20's here and there one might be able to get-by with it. but to be safe anything around 30fps+ is playable and might leave you a little room for frame rate drops as if a person is already running on the edge, it's possible during more demanding parts of a game the frame rate could end up dropping a bit too low etc, so it's nice to have a bit of a safety buffer.

note: I actually got the original Alan Wake for PC years ago through I think it was Epic Games, during a free giveaway, and I just copied the data out of that (temporarily setup a virtual machine etc) back to the general hard drive and it works totally offline with Lutris/GloriousEggroll runner for Lutris etc.

[Rubus]

What is the output of

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cat /etc/X11/xorg.conf

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cat /etc/X11/xorg.conf
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 525.89.02


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

Section "Files"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

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

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "SLI" "mosaic"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

[SMG]

The Option "SLI" "mosaic" is shown for your one display.

I found this Nvidia Partially Kills SLI In Their Latest Linux Driver which explains approximately when the change was made to SLI. Although it mentions 455.23 WHQL, which is a Windows driver, the Linux driver numbers are comparable so it appears around Nvidia-450 to 460 was when the change was probably made.

[Rubus]

Howdy everyone.

Well, my learning experiment of how to use SLI is complete. Thank you everyone for all your help teaching this newbie what and how to do what I needed to do. I sincerely appreciate all your patience and help.

Yesterday I had plenty of time to kill so I ran three benchmark tests: Heaven, Valley, and Superposition. It wasn't until I was all done that I realized Heaven and Valley only utilized one video card, and I couldn't find any settings to have them utilize both video cards. Oh well.

I think by the results I came up with we can conclude that having SLI turned on really made no difference statistically. A little better here and there, a little worse here and there, but mostly no difference.

I haven't yet played around with overclocking my video cards, so stock vs. overclocked is not included on the attached spreadsheet. I'd guess that the overclocked will have a little increase in scores, but probably not a huge difference.

Lesson learned - one higher-powered video card will likely be better than two in SLI of lower powered cards. Nothing new there, but all in all this was a fun learning experience.

[Rubus]

The Option "SLI" "mosaic" is shown for your one display.

I found this Nvidia Partially Kills SLI In Their Latest Linux Driver which explains approximately when the change was made to SLI. Although it mentions 455.23 WHQL, which is a Windows driver, the Linux driver numbers are comparable so it appears around Nvidia-450 to 460 was when the change was probably made.

Once again, my ignorance got the best of me. Your link to that article was correct - the type of SLI I was hoping to use is no longer supported. I didn't know there were so many different kinds of SLI, and my reading of the notes in the current NVIDIA driver regarding SLI made it sound to me like SLI "mosaic" was what I was wanting to enable and use. Turns out that is not the case.

Last night I was doing some more research on this and the last Linux driver I could find that still had the SLI I'm hoping for is NVIDIA-Linux-x86_64-450.119.03. I downloaded it to try and install it and see what happens. After all, this PC I built is for tinkering and learning how to do stuff like SLI and overclocking RAM and CPU. It's been quite a learning experience for a non-Techie like myself, but I sure have learned a LOT thanks to all you helpful people online. I'll call this thread closed since now I know it's a driver issue. Now - if I can just figure out how to downgrade the video driver to the one I downloaded. Thanks everyone!

[SMG]

Now - if I can just figure out how to downgrade the video driver to the one I downloaded. Thanks everyone!

You have to remove any drivers you installed using Driver Manager before installing drivers from the Nvidia website or else you can run into issue because both are installed simultaneously.

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I'm already dazed and confused, so I started a new thread specifically about installing an older driver here: viewtopic.php?t=395360

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I'm back with my SLI experimenting. I did revert to an older NVIDIA driver (390.157) that was listed as an available option in Driver Manager, and also was able to install a newer driver (450.119.03) that still had the version of SLI that I was wanting to use, and ran benchmarks. I then went through Driver Manager to the newest version (530.41.03) that no longer has SLI available and ran the same benchmarks.

In a nutshell, SLI on was WAY worse than with it off, and there wasn't much of a difference between the two older driver versions that still had SLI available to use. I was able to verify the SLI was showing as "on" with those two older versions when I had set the xorg.conf to have SLI on.

The most current driver version that no longer supports SLI did better on the Heaven and Valley benchmarks, but slightly worse or about the same on the Superposition benchmark.

My SLI testing is now complete and I have confirmed what others have said - SLI either doesn't work or isn't worth the trouble. I don't know if there's any benefit to even having two video cards in a system if they're not both going to be utilized in any way. I guess one is a spare in case the other one goes bad.

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I don't know if there's any benefit to even having two video cards in a system if they're not both going to be utilized in any way. I guess one is a spare in case the other one goes bad.

Or if you want to run multiple monitors you can have them attached to different cards.

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I have a 34" monitor that just barely fits in my desk/bookshelf setup, and my two cats are already coming up on the desk at night wanting to watch "bird movies". They get one half to watch YouTube "bird movies for cats to watch" while I try to do my thing on the other half. However, now that you mention it, I could get a second monitor and just put it on the floor for them to watch their bird movies!

A friend of mine mentioned something about "Looking Glass" and being able to fully utilize the second video card for a VM. Now that this SLI project has come to a conlusion, maybe I'll look into that.

Thank you again everyone for your time, help, and patience. Have a GREAT day!

[SMG]

I have a 34" monitor that just barely fits in my desk/bookshelf setup, and my two cats are already coming up on the desk at night wanting to watch "bird movies". They get one half to watch YouTube "bird movies for cats to watch" while I try to do my thing on the other half. However, now that you mention it, I could get a second monitor and just put it on the floor for them to watch their bird movies!

If you have questions about setting up a VM and pass-through, I suggest checking the Virtual Machines forum.