# NVIDIA/Tips and tricks

< NVIDIA

## Fixing terminal resolution

Transitioning from nouveau may cause your startup terminal to display at a lower resolution. For GRUB, see GRUB/Tips and tricks#Setting the framebuffer resolution for details.

## Using TV-out

A good article on the subject can be found here.

## X with a TV (DFP) as the only display

The X server falls back to CRT-0 if no monitor is automatically detected. This can be a problem when using a DVI connected TV as the main display, and X is started while the TV is turned off or otherwise disconnected.

To force NVIDIA to use DFP, store a copy of the EDID somewhere in the filesystem so that X can parse the file instead of reading EDID from the TV/DFP.

To acquire the EDID, start nvidia-settings. It will show some information in tree format, ignore the rest of the settings for now and select the GPU (the corresponding entry should be titled "GPU-0" or similar), click the `DFP` section (again, `DFP-0` or similar), click on the `Acquire Edid` Button and store it somewhere, for example, `/etc/X11/dfp0.edid`.

If in the front-end mouse and keyboard are not attached, the EDID can be acquired using only the command line. Run an X server with enough verbosity to print out the EDID block:

    $ startx -- -logverbose 6

After the X Server has finished initializing, close it and your log file will probably be in `/var/log/Xorg.0.log`. Extract the EDID block using nvidia-xconfig:

    $ nvidia-xconfig --extract-edids-from-file=/var/log/Xorg.0.log --extract-edids-output-file=/etc/X11/dfp0.bin

Edit `xorg.conf` by adding to the `Device` section:

    Option "ConnectedMonitor" "DFP"
    Option "CustomEDID" "DFP-0:/etc/X11/dfp0.edid"

The `ConnectedMonitor` option forces the driver to recognize the DFP as if it were connected. The `CustomEDID` provides EDID data for the device, meaning that it will start up just as if the TV/DFP was connected during X the process.

This way, one can automatically start a display manager at boot time and still have a working and properly configured X screen by the time the TV gets powered on.

If the above changes did not work, in the `xorg.conf` under `Device` section you can try to remove the `Option "ConnectedMonitor" "DFP"` and add the following lines:

    Option "ModeValidation" "NoDFPNativeResolutionCheck"
    Option "ConnectedMonitor" "DFP-0"

The `NoDFPNativeResolutionCheck` prevents NVIDIA driver from disabling all the modes that do not fit in the native resolution.

## Check the power source

The NVIDIA X.org driver can also be used to detect the GPU's current source of power. To see the current power source, check the 'GPUPowerSource' read-only parameter (0 - AC, 1 - battery):

    $ nvidia-settings -q GPUPowerSource -t

    1

## Listening to ACPI events

NVIDIA drivers automatically try to connect to the acpid daemon and listen to ACPI events such as battery power, docking, some hotkeys, etc. If connection fails, X.org will output the following warning:

    ~/.local/share/xorg/Xorg.0.log

    NVIDIA(0): ACPI: failed to connect to the ACPI event daemon; the daemon
    NVIDIA(0):     may not be running or the "AcpidSocketPath" X
    NVIDIA(0):     configuration option may not be set correctly.  When the
    NVIDIA(0):     ACPI event daemon is available, the NVIDIA X driver will
    NVIDIA(0):     try to use it to receive ACPI event notifications.  For
    NVIDIA(0):     details, please see the "ConnectToAcpid" and
    NVIDIA(0):     "AcpidSocketPath" X configuration options in Appendix B: X
    NVIDIA(0):     Config Options in the README.

While completely harmless, you may get rid of this message by disabling the `ConnectToAcpid` option in your `/etc/X11/xorg.conf.d/20-nvidia.conf`:

    Section "Device"
      ...
      Driver "nvidia"
      Option "ConnectToAcpid" "0"
      ...
    EndSection

If you are on laptop, it might be a good idea to install and enable the acpid daemon instead.

## Displaying GPU temperature in the shell

### nvidia-settings

Note: This method requires that you are using X. Use Method 2 or Method 3 if you are not. Also note that Method 3 currently does not not work with newer NVIDIA cards such as GeForce 200 series cards as well as embedded GPUs such as the Zotac IONITX's 8800GS.

To display the GPU temp in the shell, use `nvidia-settings` as follows:

    $ nvidia-settings -q gpucoretemp

This will output something similar to the following:

    Attribute 'GPUCoreTemp' (hostname:0.0): 41.
    'GPUCoreTemp' is an integer attribute.
    'GPUCoreTemp' is a read-only attribute.
    'GPUCoreTemp' can use the following target types: X Screen, GPU.

The GPU temps of this board is 41 C.

In order to get just the temperature for use in utils such as `rrdtool` or `conky`, among others:

    $ nvidia-settings -q gpucoretemp -t

    41

### nvidia-smi

Use nvidia-smi which can read temps directly from the GPU without the need to use X at all. This is important for a small group of users who do not have X running on their boxes, perhaps because the box is headless running server apps. To display the GPU temperature in the shell, use nvidia-smi as follows:

    $ nvidia-smi

This should output something similar to the following:

    $ nvidia-smi

    Fri Jan  6 18:53:54 2012
    +------------------------------------------------------+
    | NVIDIA-SMI 2.290.10   Driver Version: 290.10         |
    |-------------------------------+----------------------+----------------------+
    | Nb.  Name                     | Bus Id        Disp.  | Volatile ECC SB / DB |
    | Fan   Temp   Power Usage /Cap | Memory Usage         | GPU Util. Compute M. |
    |===============================+======================+======================|
    | 0.  GeForce 8500 GT           | 0000:01:00.0  N/A    |       N/A        N/A |
    |  30%   62 C  N/A   N/A /  N/A |  17%   42MB /  255MB |  N/A      Default    |
    |-------------------------------+----------------------+----------------------|
    | Compute processes:                                               GPU Memory |
    |  GPU  PID     Process name                                       Usage      |
    |=============================================================================|
    |  0.           ERROR: Not Supported                                          |
    +-----------------------------------------------------------------------------+

Only for temperature:

    $ nvidia-smi -q -d TEMPERATURE

    ====NVSMI LOG====

    Timestamp                           : Sun Apr 12 08:49:10 2015
    Driver Version                      : 346.59

    Attached GPUs                       : 1
    GPU 0000:01:00.0
        Temperature
            GPU Current Temp            : 52 C
            GPU Shutdown Temp           : N/A
            GPU Slowdown Temp           : N/A

In order to get just the temperature for use in utils such as rrdtool or conky, among others:

    $ nvidia-smi --query-gpu=temperature.gpu --format=csv,noheader,nounits

    52

Reference: http://www.question-defense.com/2010/03/22/gpu-linux-shell-temp-get-nvidia-gpu-temperatures-via-linux-cli.

### nvclock

Use nvclockAUR which is available from the AUR.

Note: `nvclock` cannot access thermal sensors on newer NVIDIA cards such as Geforce 200 series cards.

There can be significant differences between the temperatures reported by nvclock and nvidia-settings/nv-control. According to this post by the author (thunderbird) of nvclock, the nvclock values should be more accurate.

## Set fan speed at login

This article or section needs language, wiki syntax or style improvements.

Reason: Refer to #Enabling overclocking for description of Coolbits. (Discuss in Talk:NVIDIA/Tips and tricks#)

You can adjust the fan speed on your graphics card with nvidia-settings' console interface. First ensure that your Xorg configuration sets the Coolbits option to `4`, `5` or `12` for fermi and above in your `Device` section to enable fan control.

    Option "Coolbits" "4"

Note: GeForce 400/500 series cards cannot currently set fan speeds at login using this method. This method only allows for the setting of fan speeds within the current X session by way of nvidia-settings.

Place the following line in your xinitrc file to adjust the fan when you launch Xorg. Replace `n` with the fan speed percentage you want to set.

    nvidia-settings -a "[gpu:0]/GPUFanControlState=1" -a "[fan:0]/GPUCurrentFanSpeed=n"

You can also configure a second GPU by incrementing the GPU and fan number.

    nvidia-settings -a "[gpu:0]/GPUFanControlState=1" -a "[fan:0]/GPUCurrentFanSpeed=n" \
                    -a "[gpu:1]/GPUFanControlState=1" -a  [fan:1]/GPUCurrentFanSpeed=n" &

If you use a login manager such as GDM or KDM, you can create a desktop entry file to process this setting. Create `~/.config/autostart/nvidia-fan-speed.desktop` and place this text inside it. Again, change `n` to the speed percentage you want.

    [Desktop Entry]
    Type=Application
    Exec=nvidia-settings -a "[gpu:0]/GPUFanControlState=1" -a "[fan:0]/GPUCurrentFanSpeed=n"
    X-GNOME-Autostart-enabled=true
    Name=nvidia-fan-speed

Note: Since the drivers version 349.16, `GPUCurrentFanSpeed` has to be replaced with `GPUTargetFanSpeed`.[1]

## Manual configuration

Several tweaks (which cannot be enabled automatically or with the GUI) can be performed by editing your config file. The Xorg server will need to be restarted before any changes are applied.

See NVIDIA Accelerated Linux Graphics Driver README and Installation Guide for additional details and options.

### Disabling the logo on startup

Add the `"NoLogo"` option under section `Device`:

    Option "NoLogo" "1"

### Overriding monitor detection

The `"ConnectedMonitor"` option under section `Device` allows to override monitor detection when X server starts, which may save a significant amount of time at start up. The available options are: `"CRT"` for analog connections, `"DFP"` for digital monitors and `"TV"` for televisions.

The following statement forces the NVIDIA driver to bypass startup checks and recognize the monitor as DFP:

    Option "ConnectedMonitor" "DFP"

Note: Use "CRT" for all analog 15 pin VGA connections, even if the display is a flat panel. "DFP" is intended for DVI, HDMI, or DisplayPort digital connections only.

### Enabling brightness control

Add under section `Device`:

    Option "RegistryDwords" "EnableBrightnessControl=1"

If brightness control still does not work with this option, try installing nvidia-blAUR or nvidiablAUR.

### Enabling SLI

Warning: As of May 7, 2011, you may experience sluggish video performance in GNOME 3 after enabling SLI.
Warning: Since the GTX 10xx Series (1080, 1070, 1060, etc) only 2-way SLI is supported. 3-way and 4-way SLI may work for CUDA/OpenCL applications, but will most likely break all OpenGL applications.

Taken from the NVIDIA driver's README Appendix B: This option controls the configuration of SLI rendering in supported configurations. A "supported configuration" is a computer equipped with an SLI-Certified Motherboard and 2 or 3 SLI-Certified GeForce GPUs. See NVIDIA's SLI Zone for more information.

Find the first GPU's PCI Bus ID using `lspci`:

    $ lspci | grep VGA

    03:00.0 VGA compatible controller: nVidia Corporation G92 [GeForce 8800 GTS 512] (rev a2)
    05:00.0 VGA compatible controller: nVidia Corporation G92 [GeForce 8800 GTS 512] (rev a2)

Add the BusID (3 in the previous example) under section `Device`:

    BusID "PCI:3:0:0"

Note: The format is important. The BusID value must be specified as `"PCI:<BusID>:0:0"`

Add the desired SLI rendering mode value under section `Screen`:

    Option "SLI" "AA"

The following table presents the available rendering modes.

Value | Behavior
--- | ---
0, no, off, false, Single | Use only a single GPU when rendering.
1, yes, on, true, Auto | Enable SLI and allow the driver to automatically select the appropriate rendering mode.
AFR | Enable SLI and use the alternate frame rendering mode.
SFR | Enable SLI and use the split frame rendering mode.
AA | Enable SLI and use SLI antialiasing. Use this in conjunction with full scene antialiasing to improve visual quality.

Alternatively, you can use the `nvidia-xconfig` utility to insert these changes into `xorg.conf` with a single command:

    # nvidia-xconfig --busid=PCI:3:0:0 --sli=AA

To verify that SLI mode is enabled from a shell:

    $ nvidia-settings -q all | grep SLIMode

      Attribute 'SLIMode' (arch:0.0): AA
        'SLIMode' is a string attribute.
        'SLIMode' is a read-only attribute.
        'SLIMode' can use the following target types: X Screen.

Warning: After enabling SLI, your system may become frozen/non-responsive upon starting xorg. It is advisable that you disable your display manager before restarting.

### Enabling overclocking

Warning: Please note that overclocking may damage hardware and that no responsibility may be placed on the authors of this page due to any damage to any information technology equipment from operating products out of specifications set by the manufacturer.

Overclocking is controlled via Coolbits option in the `Device` section, which enables various unsupported features:

    Option "Coolbits" "value"

Tip: The Coolbits option can be easily controlled with the nvidia-xconfig, which manipulates the Xorg configuration files:

    # nvidia-xconfig --cool-bits=value

The Coolbits value is the sum of its component bits in the binary numeral system. The component bits are:

- `1` (bit 0) - Enables overclocking of older (pre-Fermi) cores on the Clock Frequencies page in nvidia-settings.
- `2` (bit 1) - When this bit is set, the driver will "attempt to initialize SLI when using GPUs with different amounts of video memory".
- `4` (bit 2) - Enables manual configuration of GPU fan speed on the Thermal Monitor page in nvidia-settings.
- `8` (bit 3) - Enables overclocking on the PowerMizer page in nvidia-settings. Available since version 337.12 for the Fermi architecture and newer.[2]
- `16` (bit 4) - Enables overvoltage using nvidia-settings CLI options. Available since version 346.16 for the Fermi architecture and newer.[3]

To enable multiple features, add the Coolbits values together. For example, to enable overclocking and overvoltage of Fermi cores, set `Option "Coolbits" "24"`.

The documentation of Coolbits can be found in `/usr/share/doc/nvidia/html/xconfigoptions.html`. Driver version 346.16 documentation on Coolbits can be found online here.

Note: An alternative is to edit and reflash the GPU BIOS either under DOS (preferred), or within a Win32 environment by way of nvflash[dead link 2013-05-25] and NiBiTor 6.0[dead link 2013-05-25]. The advantage of BIOS flashing is that not only can voltage limits be raised, but stability is generally improved over software overclocking methods such as Coolbits. Fermi BIOS modification tutorial

#### Setting static 2D/3D clocks

Set the following string in the `Device` section to enable PowerMizer at its maximum performance level (VSync will not work without this line):

    Option "RegistryDwords" "PerfLevelSrc=0x2222"

Categories:

- Graphics
- X server

Hidden categories:

- Pages or sections flagged with Template:Style
- Pages with dead links