Some laptops with NVIDIA GPUs make use of Optimus technology to allow switching between an integrated GPU and a discrete NVIDIA GPU. The NVIDIA Linux driver can be used on these systems, though functionality may be limited.
The driver may be installed normally on Optimus systems, but the NVIDIA X driver and the NVIDIA OpenGL driver may not be able to display to the laptop's internal display panel unless a means to connect the panel to the NVIDIA GPU (for example, a hardware multiplexer, or "mux", often controllable by a BIOS setting) is available. On systems without a mux, the NVIDIA GPU can still be useful for offscreen rendering, running CUDA applications, and other uses that don't require driving a display.
On muxless Optimus laptops, or on laptops where a mux is present, but not set to drive the internal display from the NVIDIA GPU, the internal display is driven by the integrated GPU. On these systems, it's important that the X server not be configured to use the NVIDIA X driver after the driver is installed. Instead, the correct driver for the integrated GPU should be used. Often, this can be determined automatically by the X server, and no explicit configuration is required, especially on newer X server versions. If your X server autoselects the NVIDIA X driver after installation, you may need to explicitly select the driver for your integrated GPU.
An additional caveat is that existing OpenGL libraries may be
overwritten by the install process. If you want to prevent this
from happening, e.g., if you intend to use OpenGL on the integrated
GPU, you may prevent the installer from installing the OpenGL and
GLX libraries by passing the option --no-opengl-files to the .run file, or directly to nvidia-installer,
e.g.:
# NVIDIA-Linux-x86-295.20.run --no-opengl-files
See Chapter 4, Installing the NVIDIA Driver for details on the driver install process.
In order for programs that use the NVIDIA driver to work
correctly (e.g.: X, OpenGL, and CUDA applications), the kernel
module must be loaded, and the device files /dev/nvidiactl and /dev/nvidia[0-9]+ must exist with read and write
permissions for any users of such applications. When running X with
the NVIDIA X driver, the kernel module is automatically loaded and
the device files are automatically created when X starts; however,
if X is not in use, for example, on an Optimus laptop where the
NVIDIA GPU is used to run CUDA applications only, then this must be
done separately.
The NVIDIA driver can load the kernel module and populate the device files automatically, if an application that uses the driver is run as a super user (usually root). Such applications include an X server configured to use the NVIDIA X driver, CUDA applications, and some of the utilities that are distributed with the NVIDIA driver.
For example, running:
# nvidia-xconfig --query-gpu-info
as root will cause the kernel module to be loaded, and the
device files to be created, if this hasn't already been done. Note:
the --query-gpu-info option to
nvidia-xconfig is
important here: without it, nvidia-xconfig will configure the X
server to use the NVIDIA X driver, which may prevent X from
starting later.
See “How and when are the the NVIDIA device files created?” for more information.
Note that on some Optimus notebooks the driver may fail to initialize the GPU due to system-specific ACPI interaction problems: see “Why does the VBIOS fail to load on my Optimus system?” for more information.