Why nouveau is used instead of Intel on a Intel-Optimus-Nvidia laptop?

[Simon Raffeiner (SCC)]

Hi,

there is a possible explanation for this on the nouveau page regarding
Optimus (http://nouveau.freedesktop.org/wiki/Optimus/):


"It is also possible, that a GPU is hardwired to the internal panel, so
the other GPU cannot possibly drive the internal panel. The same goes
for external monitor output. In the worst case we would have the Intel
GPU hardwired to the internal panel and the Nvidia GPU hardwired to the
external output!"


The manual for your MSI GP70 mentions the Intel GPU as "(optional)", so
they could have decided to hardwire the NVIDIA GPU to the internal
panel, which would make some sense because the device is sold as a
gaming Laptop.

I own an MSI GP60 and an IdeaPad Y580, both with Optimus, and on those
the Intel GPU is the primary one.

kind regards,
Simon




On 31.03.2015 18:30, piotr maliński wrote:
> I did a clean install of Xubuntu 15.04 beta 2 and all seems to worked
> except of some apps having slow UI animations (like text scrooling in
> Kate, slow rendering of Chromium UI, laggy YouTube in Firefox or
> Chromium). At first I was thinking that instead of Intel it's running in
> VESA mode, but after going to the drivers configuration app it turned
> out it was using nouveau which is pretty much useless. And that's on a
> MSI GP70 laptop with GT740M and i7-4700MQ.
> 
> I would suggest using Intel driver and GPU by default. It has an open
> working driver and the GPU is good. Using nouveau means poor performance
> and very bad initial experience.
> 
> I had to pick nvidia binary, then install primus, external
> "prime-indicator", reboot, switch graphics and smoke-test that on 0ad
> (had it installed, won't start if something is wrong with GPU config).


-- 
Karlsruhe Institut of Technology (KIT)
Steinbuch Centre for Computing (SCC)

M. Sc. Simon Raffeiner
High Performance Computing Administrator