What assumptions do I have to make about monitors (in OS)?

I am taking a course in Operating Systems. I am going through old exams and there is a question about monitors. We are supposed to give a solution for the producer-consumer problem using monitors. That is quite clear. But, it also says in the question:

List also the assumptions that you make about monitor semantics

Can anyone explain what is meant by this?

Two monitors in 19.04

I have two monitors in my computer but I just get one to work properly in Ubuntu 19.04…

My video card is a NVIDIA GK107 NVS 510, and I’m using the nvidia-driver-435 (also tried X.Org X Server but no luck).

xrandr gives me:

xrandr: Failed to get size of gamma for output default Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080 default connected primary 1920×1080+0+0 0mm x 0mm 1920×1080 77.00*

And lspci | grep VGA gives me:

03:00.0 VGA compatible controller: NVIDIA Corporation GK107 [NVS 510] (rev a1)

I also tried purging nvidia-* and re-selecting nvidia-driver-435 under additional drivers under software & updates.

If it helps, when I open the NVIDIA X Server Settings program I don’t actually see anything (apart from the quit and help buttons – I tried reinstalling this as well).


18.04 does not recognize monitors or drivers after graphic card change

Before I was working with build in graphic card, all worked fine. Now I set nvidia quadro p620 with DP connection.

The problem: Only one monitor recognized and it’s resolution is 800×600, nothing more than this in settings. Nvidia X server settings not load at all.

I’ve reinstalled drivers x times through console, through “sofware & updates”, in terminal mode, I’ve downloaded the driver from nvidia website and ./run it. Nothing helps.

So what I have in

xrandr  xrandr: Failed to get size of gamma for output default Screen 0: minimum 800 x 600, current 800 x 600, maximum 800 x 600 default connected primary 800x600+0+0 0mm x 0mm    800x600       75.00*      lspci -k | grep -iEA5 'vga|display|3d'   01:00.0 VGA compatible controller: NVIDIA Corporation GP107GL [Quadro P620] (rev a1)     Subsystem: NVIDIA Corporation Device 1264     Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia 01:00.1 Audio device: NVIDIA Corporation GP107GL High Definition Audio Controller (rev a1)     Subsystem: NVIDIA Corporation GP107GL High Definition Audio Controller     Kernel driver in use: snd_hda_intel 

How to make laptop use external monitors in preference to its own

So I have a Lenovo Thinkpad P51, and its graphic card (Nvidia Quadro M2200) can only support up to 4 displays. I have connected 4 monitors via its dock thus making a total of 5 displays (one being the built in monitor in the laptop). Is there a way to make it so that, maybe if I close the lid, it can utilize the 4 monitors in Ubuntu 18.04? Right now, when I close it, only the three first monitors remain. Is there a procedure to do this in Windows as well?

Thank you very much!

Monitors do not enter powersave / sleep mode after screen blanking

Ubuntu 1904, both X and Wayland. AMD 2400G, ASUS motherboard with 3 screens: HDMI,VGA,DVI.

When I leave my computer, it will blank the screen after the timeout, then my 3 monitors will fall asleep, but they will wakeup after 10 seconds or so, and never enter power save mode again. They will keep showing the lock screen.

So it is a costly affair, burning 100 Watts, and shortening lifespan of my screens.

Also when I turn off my screens manually:

xset dpms force off 

They turn off, and wake up after 10 seconds.

Could be this bug 1292041. But I doubt because it’s is also happening when powering off the screens with xset.

How do I get my screens to enter powersave mode?

Ubuntu 19.04 boots to blank screen with dual monitors and AMD Radeon HD 7730

I just loaded Ubuntu 19.04 onto my Dell XPS 8500 desktop last week. I am using an AMD Radeon HD 7730 with dual monitors (1 HDMI, 1 DisplayPort). Most of the time when I reboot my system, it will boot to a completely blank login screen. It shows nothing at all, just a blank screen. I have tried the things below and nothing is working. Deleting the raven_dmcu.bin file seemed to work but now I’m having the problem again. If anyone could please tell me how to fix this, I would very much appreciate it. I don’t want to have to buy a new video card but I’m going to have to if I can’t get this fixed. I have got all other issues on my system worked out except this one. Thanks.

1 – Tried switching monitor 1 and 2 cables and adjusting the display settings to put their left/right orientation back. 2 – I read someones post that said this would work and it did for a while but I’m having the issue again now. Delete the file /lib/firmware/amdgpu/raven_dmcu.bin and then run sudo update-initramfs -u -k all

Ubuntu 19.04 with External Monitors Closes All Applications after Sleep or Suspend and Requires 2 Logins

System: Ubuntu 19.04 – all updated are performed

MSI laptop has two external monitors; after sleep/suspend, system requires two logins. First login appears to be linux core; the second login has the newer modern UI.

After login, all applications are closed!

I have updated my NVIDIA drivers and attempted several fixes but the issue continues to exist.

Please help!

Attempted Solution: updated linux-generic (uname -r –> 5.0.0-25-generic)

Thank you :o)

Not possible to change monitor brightness for one of 2 identical monitors

At work I have a computer with two identical samsung monitors connected. The monitors have buttons to control brightness. On one of them I can just change the brightness normally. On the other one, when I open the menu using the monitors buttons, it will tell me this option is not available.
So I tried this answer, but it will only change the brightness relative to the brighntess set on the monitor. So I can only make it darker, not brighter.
I think this is not a problem with the monitor, but rather a problem with ubuntu and it’s settings. Unfortunately I don’t have sudo rights on the machine though.
Anyone has an idea, why the monitors are behaving like this?

What is a good graphics card which will drive dual 4K monitors and has decent Ubunto18.04 driver support?

Dell Optiplex 790 with a single PCIe 2.0 16X slot. I have a pair of 4K monitors and need a card that will drive them (CAD applications) clean, like automagically set up on an existing Ubuntu18.10 setup (installed 18.04, it went and upgraded itself evidently). Have seen RX550 based card suggested but these look short of connectors (1 ea, HDMI, DP and DVI). Have seen assertions that HDMI and DVI will make monitors / cards downrange the resolution, while DP has Linux support problems.

Looking for “worked for me” type recommendations that fit the machine and the monitors.