LinuxQuestions.org - Screen stuttering when using nouveau or nvidia drivers

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Screen stuttering when using nouveau or nvidia drivers

Hi everybody,

I've just installed Debian 10 (without any Desktop Environment because I wanted to install the i3wm) on my notebook Asus G75, in BIOS mode.

As soon as the system booted up for the first time, I installed

Code:

xorg, xorg-dev, build-essentials, linux-headers-4.19.0-6-amd64

.
When I tried to install the NVidia driver I've gotten from https://www.nvidia.com/Download/driv...x/137276/en-us by running

Code:

sh nvidia.run

I found out that there was an error when building the nvidia-drm module.

So I switched to the nouveau driver, installed

Code:

i3, compton

and after having configured i3 to execute compton on startup I tested my screen by using this tool https://www.testufo.com/stutter#demo...000000&pps=720 and I get video stuttering: it's like the lines are going back and forth for ~30 pixels very quickly instead of going forward.

So I tried to install the nvidia driver from the Debian package repository: I installed nvidia-detect which advised me to install nvidia-legacy-390xx-driver. When I did it, rebooted the computer, I get the very same screen stuttering effect, even after having configured the nvidia driver with nvidia-settings.

That's my hardware configuration:

Code:

00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM Controller (rev 09)

00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port (rev 09)

00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04)

00:16.0 Communication controller: Intel Corporation 7 Series/C216 Chipset Family MEI Controller #1 (rev 04)

00:1a.0 USB controller: Intel Corporation 7 Series/C216 Chipset Family USB Enhanced Host Controller #2 (rev 04)

00:1b.0 Audio device: Intel Corporation 7 Series/C216 Chipset Family High Definition Audio Controller (rev 04)

00:1c.0 PCI bridge: Intel Corporation 7 Series/C216 Chipset Family PCI Express Root Port 1 (rev c4)

00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4)

00:1c.3 PCI bridge: Intel Corporation 7 Series/C216 Chipset Family PCI Express Root Port 4 (rev c4)

00:1c.4 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 5 (rev c4)

00:1d.0 USB controller: Intel Corporation 7 Series/C216 Chipset Family USB Enhanced Host Controller #1 (rev 04)

00:1f.0 ISA bridge: Intel Corporation HM77 Express Chipset LPC Controller (rev 04)

00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04)

00:1f.3 SMBus: Intel Corporation 7 Series/C216 Chipset Family SMBus Controller (rev 04)

01:00.0 VGA compatible controller: NVIDIA Corporation GF114M [GeForce GTX 670M] (rev a1)

01:00.1 Audio device: NVIDIA Corporation GF114 HDMI Audio Controller (rev a1)

03:00.0 Network controller: Intel Corporation Centrino Wireless-N 105 (rev c4)

04:00.0 Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet (rev c0)

I also have two screens, but I'm only interested to keep the external one, as I use my notebook as a workstation.

And my software configuration is this:
- i3: the configuration file is the default one, except that I added this line near the beginning of the file

Code:

exec --no-startup-id compton --config ~/.config/compton.conf -CGb --backend glx --paint-on-overlay --vsync opengl-swc

-compton: I copied and pasted this configuration file: https://www.reddit.com/r/linuxmaster...on_this_might/

My 10-nvidia.conf file:

Code:

# nvidia-settings: X configuration file generated by nvidia-settings

# nvidia-settings:  version 390.116



Section "ServerLayout"

    Identifier    "Layout0"

    Screen      0  "Screen0" 0 0

    InputDevice    "Keyboard0" "CoreKeyboard"

    InputDevice    "Mouse0" "CorePointer"

    Option        "Xinerama" "0"

EndSection



Section "Files"

EndSection



Section "Module"

    Load          "dbe"

    Load          "extmod"

    Load          "type1"

    Load          "freetype"

    Load          "glx"

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"

    # HorizSync source: edid, VertRefresh source: edid

    Identifier    "Monitor0"

    VendorName    "Unknown"

    ModelName      "FUS P19-3P"

    HorizSync      30.0 - 82.0

    VertRefresh    56.0 - 76.0

    Option        "DPMS"

EndSection



Section "Device"

    Identifier    "Device0"

    Driver        "nvidia"

    VendorName    "NVIDIA Corporation"

    BoardName      "GeForce GTX 670M"

EndSection



Section "Screen"

    Identifier    "Screen0"

    Device        "Device0"

    Monitor        "Monitor0"

    DefaultDepth    24

    Option        "Stereo" "0"

    Option        "metamodes" "HDMI-0: 1280x1024_75 +0+0 {ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}"

    Option        "SLI" "Off"

    Option        "MultiGPU" "Off"

    Option        "BaseMosaic" "off"

    SubSection    "Display"

        Depth      24

    EndSubSection

EndSection

Do somebody have a fix? I'm quite desperate, as I've also tried to install Debian with GNOME and with KDE and I get the same artifacts with nouveau (I must admit I haven't tried the nVidia driver in that situation)
Moreover, I know I was able to configure it right the last time: I managed to install it from the .run file provided by NVidia, but I had some hardware problems a month ago and I had to change disk (and therefore to reinstall Debian). I still have the old configuration files, but they don't solve the problem in this installation.

Thanks a lot.

Please remove any configuration you (or nvidia.run) created.
Reboot.

Then please show us

Code:

lspci -k | grep -A5 VGA

grep -EC5 'EE|WW' /var/log/Xorg.0.log

The Nouveau DDX is the old technology, reverse-engineered for NVidia GPUs. The newer technology competent DDX, Modesetting, is the upstream default, included in the Xorg server package, so what you should get if you don't install the proprietary NVidia or the FOSS Nouveau (whose upstream name is xf86-video-nouveau, xserver-xorg-video-nouveau in Debian and its derivatives, various names in other distros) or any other optional video driver (xf86-video-vesa, xf86-video-fbdev). All my old NVidia GPUs, both newer and older than OP's, are running on the modesetting DDX without any apparent aberrations.

Try the 440 driver from NVIDIA and not the 390. The 390 still as issues, I had constant problems until i changed to the 440 driver.

Quote:

Originally Posted by ondoho (Post 6063583)

Please remove any configuration you (or nvidia.run) created.
Reboot.

Then please show us

Code:

lspci -k | grep -A5 VGA

grep -EC5 'EE|WW' /var/log/Xorg.0.log

I did not use nvidia.run to install the driver, I used the debian package

Code:

nvidia-legacy-390xx-driver

, but before installing it, I run

Code:

sh nvidia.run --uninstall

in order to clean the previous attempt of installation.

Here is the output of the commands you asked:

lspci -k | grep -A5 VGA

Code:

01:00.0 VGA compatible controller: NVIDIA Corporation GF114M [GeForce GTX 670M] (rev a1)

        Subsystem: ASUSTeK Computer Inc. GF114M [GeForce GTX 670M]

        Kernel driver in use: nvidia

        Kernel modules: nvidia

01:00.1 Audio device: NVIDIA Corporation GF114 HDMI Audio Controller (rev a1)

        Subsystem: NVIDIA Corporation GF114 HDMI Audio Controller

grep -EC5 'EE|WW' /var/log/Xorg.0.log

Code:

[    15.410] Current version of pixman: 0.36.0

[    15.410]        Before reporting problems, check http://wiki.x.org

        to make sure that you have the latest version.

[    15.410] Markers: (--) probed, (**) from config file, (==) default setting,

        (++) from command line, (!!) notice, (II) informational,

        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.

[    15.412] (==) Log file: "/var/log/Xorg.0.log", Time: Mon Dec  2 19:00:29 2019

[    15.414] (==) Using system config directory "/usr/share/X11/xorg.conf.d"

[    15.416] (==) No Layout section.  Using the first Screen section.

[    15.416] (==) No screen section available. Using defaults.

[    15.416] (**) |-->Screen "Default Screen Section" (0)

--

        Using a default monitor configuration.

[    15.417] (==) Automatically adding devices

[    15.417] (==) Automatically enabling devices

[    15.417] (==) Automatically adding GPU devices

[    15.417] (==) Max clients allowed: 256, resource mask: 0x1fffff

[    15.419] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.

[    15.419]        Entry deleted from font path.

[    15.421] (==) FontPath set to:

        /usr/share/fonts/X11/misc,

        /usr/share/fonts/X11/100dpi/:unscaled,

        /usr/share/fonts/X11/75dpi/:unscaled,

--

[    15.737] (II) Module nouveau: vendor="X.Org Foundation"

[    15.737]        compiled for 1.20.3, module version = 1.0.16

[    15.737]        Module class: X.Org Video Driver

[    15.737]        ABI class: X.Org Video Driver, version 24.0

[    15.737] (II) LoadModule: "nv"

[    15.737] (WW) Warning, couldn't open module nv

[    15.737] (EE) Failed to load module "nv" (module does not exist, 0)

[    15.737] (II) LoadModule: "modesetting"

[    15.738] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so

[    15.739] (II) Module modesetting: vendor="X.Org Foundation"

[    15.739]        compiled for 1.20.4, module version = 1.20.4

[    15.739]        Module class: X.Org Video Driver

--

[    15.746]        compiled for 1.20.4, module version = 1.0.0

[    15.746]        ABI class: X.Org ANSI C Emulation, version 0.4

[    15.746] (II) Loading sub module "ramdac"

[    15.746] (II) LoadModule: "ramdac"

[    15.746] (II) Module "ramdac" already built-in

[    15.748] (WW) Falling back to old probe method for modesetting

[    15.748] (WW) Falling back to old probe method for fbdev

[    15.748] (II) Loading sub module "fbdevhw"

[    15.748] (II) LoadModule: "fbdevhw"

[    15.748] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so

[    15.749] (II) Module fbdevhw: vendor="X.Org Foundation"

[    15.749]        compiled for 1.20.4, module version = 0.0.2

[    15.749]        ABI class: X.Org Video Driver, version 24.0

[    15.749] (EE) open /dev/fb0: No such file or directory

[    15.749] (II) NVIDIA(0): Creating default Display subsection in Screen section

        "Default Screen Section" for depth/fbbpp 24/32

[    15.749] (==) NVIDIA(0): Depth 24, (==) framebuffer bpp 32

[    15.749] (==) NVIDIA(0): RGB weight 888

[    15.749] (==) NVIDIA(0): Default visual is TrueColor

--

[    16.426] (II) Initializing extension XFIXES

[    16.426] (II) Initializing extension RENDER

[    16.426] (II) Initializing extension RANDR

[    16.426] (II) Initializing extension COMPOSITE

[    16.426] (II) Initializing extension DAMAGE

[    16.426] (II) Initializing extension MIT-SCREEN-SAVER

[    16.426] (II) Initializing extension DOUBLE-BUFFER

[    16.426] (II) Initializing extension RECORD

[    16.427] (II) Initializing extension DPMS

[    16.427] (II) Initializing extension Present

[    16.427] (II) Initializing extension DRI3

Quote:

I tried to install only the package xorg, but I get a worse screen tearing effect along with the screen stuttering.

Quote:

Try the 440 driver from NVIDIA and not the 390. The 390 still as issues, I had constant problems until i changed to the 440 driver.

I'm going to try it right now.

Anyway, I found another configuration for the 10-nvidia.conf file which, although it did not solve the screen stuttering issue, it surely helped in making it less noticeable:

Code:

# nvidia-settings: X configuration file generated by nvidia-settings

# nvidia-settings:  version 390.116



Section "ServerLayout"

    Identifier    "Layout0"

    Screen      0  "Screen0" 0 0

    InputDevice    "Keyboard0" "CoreKeyboard"

    InputDevice    "Mouse0" "CorePointer"

    Option        "Xinerama" "0"

EndSection



Section "Files"

EndSection



Section "Module"

    Load          "dbe"

    Load          "extmod"

    Load          "type1"

    Load          "freetype"

    Load          "glx"

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"

    # HorizSync source: edid, VertRefresh source: edid

    Identifier    "Monitor0"

    VendorName    "Unknown"

    ModelName      "FUS P19-3P"

    HorizSync      30.0 - 82.0

    VertRefresh    56.0 - 76.0

    Option        "DPMS"

EndSection



Section "Device"

    Identifier    "Device0"

    Driver        "nvidia"

    VendorName    "NVIDIA Corporation"

    BoardName      "GeForce GTX 670M"

    Option        "NoLogo" "1"

    Option        "RenderAccel" "1"

    Option        "TripleBuffer" "true"

    Option        "MigrationHeuristic" "greedy"

    Option        "AccelMethod" "sna"

    Option        "TearFree"    "true"

EndSection



Section "Screen"

    Identifier    "Screen0"

    Device        "Device0"

    Monitor        "Monitor0"

    DefaultDepth    24

    Option        "Stereo" "0"

    Option        "metamodes" "HDMI-0: 1280x1024_60 +0+0 {ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}"

    Option        "SLI" "Off"

    Option        "MultiGPU" "Off"

    Option        "BaseMosaic" "off"

    SubSection    "Display"

        Depth      24

    EndSubSection

EndSection

Thanks a lot for your replies.

Quote:

Originally Posted by Bp_Tec (Post 6063676)

Try the 440 driver from NVIDIA and not the 390. The 390 still as issues, I had constant problems until i changed to the 440 driver.

I tried executing

Code:

apt purge nvidia-*

and then

Code:

apt install nvidia-driver

but it gives an error I have attached to this thread.

EDIT: that's the second reply I make to this thread, the first one contains all the details asked by ondoho and a question for mrmazda: the system said that it was awaiting for ad admin approval, but I don't know how this reply is not waiting too...

Quote:

Originally Posted by LuxGiammi (Post 6063995)

I tried executing

Code:

apt purge nvidia-*

Is that what the instructions accompanying installation of that driver said? Simply purging does not always reverse every change that NVidia installation causes.

Also, that error message in the screenshot is incorrect about there being only two choices of driver, as my previous post explained. I recommend trying the modesetting DDX if you can be sure all of the proprietary changes have been reversed. It cannot work if nouveau has been blacklisted, or if a modified library is not also purged. It requires a totally FOSS X environment.

Quote:

Originally Posted by mrmazda (Post 6064002)

I remember that there was a library that the nvidia driver overwrote during installation. So I might better try with a fresh Debian installation.
Also, I'm sorry but I have to ask some more information about "modesetting DDX". I googled for mdesetting DDX, and I found some articles which explains that I should install

Code:

xf86-video-intel

. However, the Arch Linux wiki states that it has caused some issues in Debian... https://wiki.archlinux.org/index.php...s#Installation. So I'm a bit confused about what I should do after I have a functioning Debian installation on another disk partition: what package should I install (or what settings should I tweak) to use the "modesetting DDX"?

Thanks in advance.

Most AMD, Intel and and NVidia APUs (IGPs) and GPUs that are neither antique nor newer than the software are automatically supported by the modesetting DDX. No configuration or additional packages should be necessary to cause use of the modesetting DDX. For Debian 10 this equates to not installing xserver-xorg-video-nouveau.

If an Intel GPU is present, installing xf86-video-intel on a distro that does not change the upstream names of their DDXes will normally cause the ancient intel DDX to be used instead of the newer technology modesetting DDX.

Quote:

Originally Posted by mrmazda (Post 6064019)

Actually, I believe that the package you mentioned comes by default with Debian (or with xorg). I tried executing the command

Code:

sudo apt list | grep nouveau

libdrm-nouveau2/stable,now 2.4.97-1 amd64 [installed,automatic]

xserver-xorg-video-nouveau/stable,now 1:1.0.16-1 amd64 [installed,automatic]

but I do not remember having installed that package manually. This means that either xorg or the debian installer must have installed it... Anyway, tomorrow I'll try to make a fresh debian installation on another partition of my disk, so that I'll be able to check if it comes pre-installed with either debian or xorg. If it was the case, what should I do? You said that purging a package is not as uninstalling it but how can I prevent whatever installs it to install it?

Thanks in advance.

Upstream, xf86-video-* are all optional. Most distros bundle them all as a meta-package and install by default along with their standard Xorg patterns. Debian's meta is xserver-xorg-video-all. You can purge any individual driver (xserver-xorg-video-nouveau in your Debian), or the whole meta-package bundle, and if your GPU is supported by it, X will run on the modesetting DDX provided by the server package. There's absolutely no reason to reinstall and try to prevent the meta from being installed. The only obstacle to reusing the existing installation would be if it's found impossible to properly eradicate an installed proprietary driver.

It's not necessary to purge xserver-xorg-video-nouveau to utilize the modesetting DDX. It can be specified as the driver to use via a Device section in an /etc/X11/xorg.conf* file, as can any other driver that "supports" your GPU, however poorly or well as it may.

Naturally, there's no guarantee using the modesetting DDX will have an impact on the stuttering. All you can do is try it.

Quote:

Originally Posted by mrmazda (Post 6064066)

Thanks for your reply and sorry for the delay I'm posting my reply with.

I've tried a fresh installation of Debian. I installed xorg, i3 and compton. I've configured compton and i3 as before, but now I tried to use the command

Code:

X -configure

to generate the xorg.conf file. I tried to change the driver used by the X server, but I did not succeded in doing that. I've also tried to blacklist nouveau, but then I could not start the X server.

Here's the configuration I used

Code:

Section "ServerLayout"

        Identifier    "X.org Configured"

        Screen      0  "Screen0" 0 0

        InputDevice    "Mouse0" "CorePointer"

        InputDevice    "Keyboard0" "CoreKeyboard"

EndSection



Section "Files"

        ModulePath  "/usr/lib/xorg/modules"

        FontPath    "/usr/share/fonts/X11/misc"

        FontPath    "/usr/share/fonts/X11/cyrillic"

        FontPath    "/usr/share/fonts/X11/100dpi/:unscaled"

        FontPath    "/usr/share/fonts/X11/75dpi/:unscaled"

        FontPath    "/usr/share/fonts/X11/Type1"

        FontPath    "/usr/share/fonts/X11/100dpi"

        FontPath    "/usr/share/fonts/X11/75dpi"

        FontPath    "built-ins"

EndSection



Section "Module"

        Load  "glx"

EndSection



Section "InputDevice"

        Identifier  "Keyboard0"

        Driver      "kbd"

EndSection



Section "InputDevice"

        Identifier  "Mouse0"

        Driver      "mouse"

        Option            "Protocol" "auto"

        Option            "Device" "/dev/input/mice"

        Option            "ZAxisMapping" "4 5 6 7"

EndSection



Section "Monitor"

        Identifier  "Monitor0"

        VendorName  "Monitor Vendor"

        ModelName    "Monitor Model"

EndSection



Section "Device"

        ### Available Driver options are:-

        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",

        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",

        ### <percent>: "<f>%"

        ### [arg]: arg optional

        #Option    "SWcursor"                  # [<bool>]

        #Option    "HWcursor"                  # [<bool>]

        #Option    "NoAccel"                    # [<bool>]

        #Option    "ShadowFB"                  # [<bool>]

        #Option    "VideoKey"                  # <i>

        #Option    "WrappedFB"                  # [<bool>]

        #Option    "GLXVBlank"                  # [<bool>]

        #Option    "ZaphodHeads"                # <str>

        #Option    "PageFlip"                  # [<bool>]

        #Option    "SwapLimit"                  # <i>

        #Option    "AsyncUTSDFS"                # [<bool>]

        #Option    "AccelMethod"                # <str>

        #Option    "DRI"                        # <i>

        Identifier  "Card0"

        Driver      "modesetting"

        BusID      "PCI:1:0:0"

EndSection



Section "Screen"

        Identifier "Screen0"

        Device    "Card0"

        Monitor    "Monitor0"

        SubSection "Display"

                Viewport  0 0

                Depth    1

        EndSubSection

        SubSection "Display"

                Viewport  0 0

                Depth    4

        EndSubSection

        SubSection "Display"

                Viewport  0 0

                Depth    8

        EndSubSection

        SubSection "Display"

                Viewport  0 0

                Depth    15

        EndSubSection

        SubSection "Display"

                Viewport  0 0

                Depth    16

        EndSubSection

        SubSection "Display"

                Viewport  0 0

                Depth    24

        EndSubSection

EndSection

I've also found out the command `inxi` during my research. Here is the output of `inxi -Gxx`:

Code:

Graphics:  Device-1: NVIDIA GF114M [GeForce GTX 670M] vendor: ASUSTeK driver: nouveau v: kernel bus ID: 01:00.0 

          chip ID: 10de:1213 

          Display: server: X.Org 1.20.4 driver: amdgpu,ati,fbdev,intel,modesetting,nouveau,radeon,vesa,vmware 

          compositor: compton resolution: 1920x1080~60Hz, 1280x1024~60Hz 

          OpenGL: renderer: NVCE v: 4.3 Mesa 18.3.6 direct render: Yes

It seems like the Intel Graphics Card has not been found...

Thanks in advance.

Quote:

Originally Posted by LuxGiammi (Post 6065073)

Code:

X -configure

This is virtually always a waste of time, potentially making it impossible to determine what when something goes haywire. Modern automagic X configuration is highly competent. However....

Quote:

Code:

inxi -Gxx

Graphics:  Device-1: NVIDIA GF114M [GeForce GTX 670M] vendor: ASUSTeK driver: nouveau v: kernel bus ID: 01:00.0 

          chip ID: 10de:1213 

          Display: server: X.Org 1.20.4 driver: amdgpu,ati,fbdev,intel,modesetting,nouveau,radeon,vesa,vmware 

          compositor: compton resolution: 1920x1080~60Hz, 1280x1024~60Hz 

          OpenGL: renderer: NVCE v: 4.3 Mesa 18.3.6 direct render: Yes

It seems like the Intel Graphics Card has not been found...

This is the first apparent indication produced here that this laptop has hybrid (or dual) graphics. Usually there is an Optimus label somewhere discoverable, such as a sticker or a section in the manual, when both Intel and NVidia graphics are present. In such cases special configuration instructions must be followed, either Prime/BBSswitch or Bumblebee in most cases.

Quote:

Originally Posted by mrmazda (Post 6065106)

This is virtually always a waste of time, potentially making it impossible to determine what when something goes haywire. Modern automagic X configuration is highly competent. However....

This is the first apparent indication produced here that this laptop has hybrid (or dual) graphics. Usually there is an Optimus label somewhere discoverable, such as a sticker or a section in the manual, when both Intel and NVidia graphics are present. In such cases special configuration instructions must be followed, either Prime/BBSswitch or Bumblebee in most cases.

I tried to look for that label or the text "Optimus" in my laptop's manual. By making a quick search online I found this thread which last reply states that my laptop does not have optimus enabled.

I did some more experiments this week and I found out two thigs:
1. The screen tearing issue was an issue with Firefox only (setting the option layers.acceleration.force-enabled to true has prevented the screen from tearing)
2. I managed to find out that the screen "trembles": I tried to download a video which shows some white lines moving and I see them trembling on screen (I used mpv to play the video).

I also tried to do another experiment installing Bumblebee (from this guide): as soon as I try to install it I get a warning very very similar to the one I attached the screenshot of in a post on this thread approximately 10 days ago (the driver is not compatible with your configuration, blah blah blah).

I'm happy that at least the tearing disappeared, but the "trembling" is very annoying. Could it be an issue with the operating system? My laptop is not "new" (I bought it in 2012); moreover, one day I found out a company called Slimbook, which sells computers with GNU/Linux installed: if you configure a computer selecting an nVidia card and Debian as your OS they warn you that you will have some compatibility issues. That's just an hypothesis, but...

Thanks in advance.