Configuring multiple RTX A4000 GPUs as a single xscreen on Linux RedHawk 8.4.1

I’m attempting to use two RTX A4000 GPUs to support 4 monitors with edge blending software. I need to configure all 4 monitors into a single xscreen0 with /etc/X11/xorg.conf. Based on the spec sheet, the RTX A4000 GPUs appear to not support SLI. I have attempted to use BaseMosaic as I have used this in the past with three older GeForce cards to achieve a similar effect.

Related topic: Configuring multiple RTX A4000 GPUs as a single Screen 0 on Linux RedHawk 6.5.6

The above thread is identical aside from the RedHawk version, and so the same questions that were posted there apply.

  • Does the RTX A4000 GPU support BaseMosaic?
  • Does the RTX A4000 GPU support SLI Mosaic if used with the Quadro Sync II card?

Hi there @joseph.j.figaniak , welcome to the NVIDIA developer forums

While I am not able to help you myself, I will reach out to someone who might.

Thank you for your patience!

UPDATE: I wound up exhausting all other options and was able to get a version of from Concurrent and I have a working xorg.conf using BaseMosaic with two RTX A4000 GPUs without any other connections. I also tested this config with two Quadro P5000 GPUs without any other connections.

Background - Previously was using 470.74 Nvidia driver provided by Concurrent as I am using RedHawk kernel, and as soon as I would enable BaseMosaic in the xorg.conf file, I would get an odd error in Xorg.0.log stating “PCIXX is part of an active SLI configuration”. I was able to get the cards to form two separate xscreens with both cards enabled, but as soon as I would enable BaseMosaic, the “active SLI connection” error would show up. This would occur with no other connections on the GPUs, just two GPUs connected to PCI slots on the mobo.

I attempted to use the Quadro Sync II card with the RTX A4000 GPUs and SLI cables with the Quadro P5000 GPUs along with SLI Mosaic settings in the xorg.conf with no luck. The same “active SLI connection” error would show up in logs.

I then attempted to use Nvidia driver 470.92 with RedHat 4.18.0-372.26.1.el8_6.x86_64 kernel to rule out RedHawk as my issue and again had the same errors.

I was recently able to get a compatible Nvidia driver of 515.48.07 from Concurrent to use with the RedHawk kernel and immediately had success using BaseMosaic settings in the xorg.conf file.

At this point I believe we were up against a bug with the 470.XX driver, these cards, and our motherboard. I have not determined exactly the issue, but my hunch is the motherboard did not communicate properly with the driver.

For reference the mobo model and BIOS version are below:
Supermicro X11DPi-N

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.