Multi display not working with RHEL 7.2 64 bit using 375.66 driver

Hi All,

I am unable to get dual displays work with the latest NVIDIA driver 375.66 and RHEL 7.2

I am using module.which is having splitter DVI Y for display, where One output is connected to DVI display and another is connected to VGA display (using DVI to VGA converter).

Now the problem is as follows,

  1. When system starts booting, splash screen comes in VGA (monitor2) and then GUI display comes to DVI (monitor1).
  2. We have changed the DVI monitor with different(lower) resolution but GUI display not came in DVI (monitor1).
  3. When we have checked xrandr command, it is detecting only one display, in Xorg logs also it is showing one display.

Can you suggest for above problems,

  1. We have to get GUI display (clone or extended) in both the monitors.
  2. How to make different monitors work in DVI with various resolution options
  3. how to make 2nd monitor to be detected.

Sai Krishna
nvidia-bug-report.log.gz (222 KB)
xorg.conf.txt (11.9 KB)
xorg.conf-xorg-config.txt (1.37 KB)
gpu-info.txt (704 Bytes)
ipn250rm.pdf (1 MB)

Adding Option “ModeDebug” “True” in your xorg.conf file or run command nvidia-xconfig --mode-debug, Start X/Graphical desktop. or As soon as you hit this issue please generate nvidia bug report and attach to your existing post. Are you able to detect display with display property tool of os oe with nvidia-settings tool?

Hi Sandip,

I Have attached the report.
I am not able to detect 2nd monitor with either settings.

>>When system starts booting, splash screen comes in VGA (monitor2) and then GUI display comes to DVI (monitor1).

Can you attach both DVI display to DVI Y splitter and test? Also check which display is set as primary display in display property tools and nvidia-settings tool. Please share video recording showing this issue to understand. Does your setup ever worked with Two displays lights up? Did you try hot-plugin display once GUI/Desktop appears?

Hi Sandip,

  1. We have connected both DVI display to DVI Y splitter, Only one display is coming i.e. from splitter 1(Monitor 1).

  2. We are unable to share the video recording because of security issues.

  3. Yes, the setup worked with Two displays lights up when RHEL 7.2 OS was installed.

  4. We got the dispalys as follows:

    a) In splitter 1 - only DVI (Monitor1) as Secondary display

    b) In splitter 2 - only VGA (Monitor2) as Primary display

5)No, we didn’t try hot-plugin display once GUI/Desktop

Kindly, suggest any solution at the earliest.

Is the same splitter device/hardware is working with RHEL 7.2? Did you try changes splitter with other one? Is the Active or Passive splitter/dongle? Please try hot-plugin display by disconnecting and reconnecting cables.

Yes, It is a same splitter working with RHEL 7.2. Yes we have tried changing the splitter with other, there is no change in output.

Now, what I observed is when I am giving [Alt+crtl+F2], the termnial comes in VGA (Monitor2).

But when I am coming back to GUI and checking for nvidia-settings display, only one display detecting i.e. DVI Out (Monitor1).

So, all CLI comes in VGA and GIU comes in DVI.

>>3) Yes, the setup worked with Two displays lights up when RHEL 7.2 OS was installed.
You mean this setup was working earlier with two displays? So what is recent change that made this issue?

>>So, all CLI comes in VGA and GUI comes in DVI.
That’s interesting. That mean both display actually detected by OS and GPU. I think you have to configure you xorg.conf manually to lightup both displays.

Recent change is Only I have installed Nvidia driver after disabling nouveau driver, apart from that nothing have been done.

If both display is detected by OS and GPU, why it is not showing in nvidia-settings?

Please find my xorg.conf file attached,let me know for any suggestions.

I have configured for multiple displays, even if limiting to 2 displays it didn’t work.

Backup your existing xorg.conf file and run nvidia-xconfig to generated new default one. start X and see what happens. Also test with nvidia-xconfig --separate-x-screens and nvidia-xconfig -a . Check what happens after X starts.

If we want to replicate this issue to debug further can you tell how you are using module so we can prepare setup. Any special configuration needed or any desktop/workstation system is okay for this module.

Can you please test with drivers from ?

Also please share output of comamnd nvidia-xconfig --query-gpu-info .

  1. When nvidia-xconfig is used, nothing is coming in display, after adding BusID in the xorg.conf configuration file GUI display comes in DVI. CLI comes in VGA.Please find the attached conf file as xorg.conf-xorg-config.txt.

2)Earlier I have attached the xorg.conf file i.e. with nvidia-xconfig --separate-x-screens, no change in output, same as above.

  1. When nvidia-xconfig -a is used, one additional parameter BoardName “EXK107” is added after change in output, same as 1.

Yes, to debug a special set up is required,

a) We are using VPX backplane technology

b) We are using IPN251 SINGLE BOARD COMPUTER with Rear Transistion Module- IPN250 where all I/O functioning modules can be accessed at the rear. Please find the attachment of IPN-RTM250 pdf

c) One Dual DVI link ( DMS-59) male splitter cable with two DVI ports

d) DVI/VGA cables and monitors.

  1. We tried all the drivers, there is no luck.

  2. Please find the gpu-info attached.

>>Please find the attachment of IPN-RTM250 pdf
I didn’t find it attached. So does your module has DMS-59 port from where you connect two DVI display ? Can you share photo?

But how we can replicate this issue to further investigate?

Hi saikrishna,
Logs are not providing more information to root cause the issue. Can you get the support from the Vendor who provided you this module and system? May they have direct official contact with NVIDIA from where we can get the same hardware and system and then try to replicate and investigate this issue.

Hi Sandip,

Please find the IPN-RTM250.pdf.

In that document, section 2.4.3 for connections and figure 2-3 is the DMS-59 pin connector, we are using.

OK, I will try to contact vendor, mean time we want support from you also.

Okay. Are you using DMS-59 to two DVI-I Dual link dongle ? Are you using port J7 on IPN250 module?

“The IPN250 provides one DVI‐I or VGA output from the GPU and one VGA‐only output from the GMCH.”
Do you know what is GMCH? Does it mean one output from gpu active at a one time? Check with support.