Re:Hybrid graphics support in Nvidia 's Linux driver
by tmurray on Monday September 03, 2012 @06:29PM
(#4472070)
The lack of any sort of physical connection to the NVIDIA GPU's display outputs is the fundamental feature of Optimus. Switchable graphics existed for years before Optimus introduced (and was usually usable under Linux without issue), but it was largely a niche feature because of the usability drawbacks.
I was not aware of this fact.
> the Intel GPU to be connected to the display hardware and be used most of the time...the NVIDIA GPU is enabled on the fly...
I did mention these aspects of Optimus.
> rendering is done on the NVIDIA GPU, and the final result is sent in some way to the Intel GPU, which can then use its actual display connections to put something on the LCD.
I guess I missed the point that the architecture is like this:
nVidia <-> Intel <-> Display
instead of like this:
Display <-> nVidia
Display <-> Intel
I was a little fuzzy on this point myself, so I appreciate the clarification!
> the infrastructure for the actual sharing of the rendered output didn't really exist until dmabuf appeared
I'd certainly believe that the current approach to the nVidia driver was enabled by dmabuf. But Bumblebee shows it's possible to use Optimus on Linux without that particular kernel feature.