Nvidia Optimus

Nvidia Optimus is an optimization technology created by Nvidia to save battery life by automatically switching the power of the graphics processing unit (GPU) off when it is not needed and switching it on when needed again. The technology mainly targets mobile PCs such as notebooks.^[1] When the GPU power is off, the driver redirects graphics commands to the integrated graphics chip (e.g. Intel GMA). Currently only Windows 7 is officially supported, however the open source project Bumblebee brings support to Linux.

Linux support

Nvidia has no plans to support Optimus on Linux.^[2]

In addition to lack of support for switching between GPU chipsets, the presence of Optimus can actually prevent the use of Nvidia chipset, even if installed GPU drivers support it.^[3] Some older systems contain a hardware switch (mux) to switch the output between the two video devices, which could be set in the BIOS. Modern systems lack the hardware muxer and output is often hardwired to integrated chipset's display controller. With Optimus, the output frames from the Nvidia card are therefore transferred over the PCIe bus to the integrated chipset's framebuffer, which is then displayed. This transfer is not working using official driver on anything except Windows 7 because of lacking architectural infrastructure of other operating systems.

The open-source project Bumblebee tries to support these kind of graphics cards.

Problems

The technology however is plagued with a variety of issues that cause it to not switch to the more powerful gpu, defaulting to the integrated video card even when the gpu is selected. This is a major issue, especially for people with gaming laptops because it effectively renders their powerful video cards useless.

See also

• ATI Hybrid Graphics/PowerXpress, a similar technology by AMD

References

http://www.thinkdigit.com/Laptops-PCs/36-of-the-latest-laptops-from-Asus_4309.html

1. ^ http://www.nvidia.com/object/optimus_technology.html
2. ^ "We have no plans to support Optimus on Linux at this time.", ', February 10, 2010, accessed November 27, 2010.
3. ^ "On laptops that don't have that hardware mux you currently cannot use the NVIDIA GPU for display.", ', July 23, 2010, accessed November 27, 2010.