Nvidia GPU runs hot

[Rick Timmis]

Originally reported on Kubuntu mailing list, by 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.

[Mitch Golden (mgolden)]

This is what I wrote on the kubuntu-devel list in response.

---

My concern is that this bug is sort of a worst-case scenario, as far as responsability goes. The bug by itself is
quite serious - but it's not clear who fixes it. It isn't probably a kubuntu packaging issue. It may be a plasma 5 kde (upstream) issue. It is I guess even more likely to be a combination of plasma 5 and nvidia driver issue - in which case I don't know where to report it because that driver is proprietary.

The installer actually supplies the open-source nouveau driver. There is no control panel that reports the clock speed under nouveau. From the sound of the fan I am guessing that nouveau is also running the clock at a high rate a lot of the time.

At the very least all of this should be looked into by someone who knows more about it than it - preferably before the decision to make Kubuntu 15.04 be plasma 5 is permanently taken.

[Phillip Susi (psusi)]

Well, this doesn't seem to have anything to do with the installer. Unless using the same nvidia driver without the kde desktop ( i.e. under gnome or xfce ) shows totally different behavior, then it looks like this is simply how the proprietary nvidia driver works so there's nothing we can do about it. For what it's worth, ATI cards seem to have always worked the same way, though recently they have gained dynamic power management so they at least lower their clock rate when not in heavy use and that saves some power and heat.

[Launchpad Janitor (janitor)]

[Expired for xorg (Ubuntu) because there has been no activity for 60 days.]