Ubuntu – Hearthstone Ubuntu 15.04

First undo everything that you did from the guide you linked to in your question, including uninstalling all the packages that you installed by following the guide and undoing the edits to files that you edited. Uninstall the Nvidia proprietary graphics driver and reboot the computer.

Open the terminal and type:

sudo apt install nvidia-346 nvidia-settings nvidia-prime
sudo reboot  

Nvidia Prime is a more up to date replacement for Bumblebee. Using Nvidia graphics drivers with initial Optimus support in Ubuntu is easier with Nvidia Prime. Nvidia Prime is not supported on some older models of laptops, however it is supported on the Lenovo IdeaPad Y510p laptop.

After the computer reboots, you will be able to switch between NVIDIA (Performance Mode) and Intel (Power Saving Mode) graphics from the NVIDIA Settings utility.

I had similar a problem with a K2000M on my laptop and using Linux Mint Cinnamon 17.2.

Expecially using a second monitor, video tearing appeared on my primary display.

The solution was to use ForceFullCompositionPipeline together with TripleBuffer

First do sudo nvidia-xconfig if the X11 configuration file xorg.conf is absent, then

sudo nano /etc/X11/xorg.conf

and add the line Option "TripleBuffer" "On" under the Section "Screen":

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "TripleBuffer" "On"
    Option         "nvidiaXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "LVDS-0: 1920x1080_60 +0+840, DP-4: 1920x1080_60 +1920+0 {rotation=left}"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

In order to be able to use ForceFullCompositionPipeline = On, one could modify the line Option "metamodes" in xorg.conf, but the problem was that when using a secondary monitor, the monitors.xml file (for the display manager) in ~/.config was overriding any modification issued by X11 reading xorg.conf at login (see here).

The solution for me was to run a script at login (using System -> Preferences -> Startup Applications) with the following command:

nvidia-settings --assign="CurrentMetaMode=LVDS-0: 1920x1080_60 +0+840 { ForceFullCompositionPipeline = On }, DP-4: 1920x1080_60 +1920+0 { ForceFullCompositionPipeline = On, rotation=left }"

where LVDS-0 is my primary display and DP-4 my secondary display (use xrandr -q for the display names)

The last lines of /var/log/Xorg.0.log now shows:

...
[   136.640] (II) NVIDIA(0): Setting mode "LVDS-0:1920x1080_60+0+840{ForceFullCompositionPipeline=On},DP-4:1920x1080_60+1920+0{ForceFullCompositionPipeline=On,rotation=left}"
...

and the video tearing disappeared...

Hope this helps on Ubuntu