Plasma 5 on nvidia

[Mitch Golden]

I am posting this here because I don't know exactly where it should be 
posted.

I have installed 14.10 Plasma 5 on my laptop, which is a vintage 2011 
System 76.  Of greatest significance is that it has an nvidia 560M 
graphics card in it.

When I first installed 14.04, I noticed that the PowerMizer report of the 
NVIDIA X Server Settings would report that the graphics chip's clock was 
more or less constantly spun up to its highest clock rate.  Heat and power 
use were very high, and I constantly heard the fan running.

I found there were two ways to fix this:

(1) Add a file called 05-nvidia.conf to /usr/share/X11/xorg.conf.d 
containing the lines:

Section "Device"
     Identifier     "Device0"
     Driver         "nvidia"
     VendorName     "NVIDIA Corporation"
     Option         "RegistryDwords" "PowerMizerEnable=0x1; PerfLevelSrc=0x2222; PowerMizerDefault=0x3; PowerMizerDefaultAC=0x3"
EndSection

This pegged the graphics card at its lowest possible clock rate, which was 
adequate for most things but sometimes led to bad playback on some videos.

See: https://forums.opensuse.org/showthread.php/410089-nvidia-powermizer-how-tweak

(2) Revert to the 304 driver.  This still spun up to high clock rates a 
bit more often than it seemed to need to, but was fairly reasonable 
otherwise.

I expected that this would soon be rectified, since I saw that version 
337.25 of the driver allegedly fixed some issue with performance in KDE:

http://www.nvidia.com/download/driverResults.aspx/76278/en-us



Jump ahead to yesterday when I installed 14.10 plasma 5 -

I noticed that even with the 304 driver the PowerMizer reported the clock 
at its highest rate.  With nothing moving on the screen at all and my not 
touching the mouse, it was pegged.

I found that even installing the xorg-edgers driver (340 I believe) had no 
effect.  Furthermore, 340 did not respond to the xorg.conf settings file 
above.  The only way I can get plasma 5 to run reasonably on this machine 
is to revert to 304 and *also* put the settings file in.  This is of 
course not optimal.


Perhaps the installer can be made to configure this stuff properly for 
nvidia machines, or at least instructions can be added.


I have additional bugs/comments to make on the behavior of plasma 5.  I 
don't see any instructions on the download place as to where they should 
go.  Pointers kindly appreciated.

   - Mitch Golden