How to switch Ubuntu 16.04 back to using your NVidia graphic card

I am not a smart person. Almost two months after upgrading to using Ubuntu 16.04 LTS I finally realized it'd not been using the NVIDIA graphic card inside my laptop.

This couple weeks I've been playing Left 4 Dead 2 again with Master Tso, and it always froze from time to time. I thought it was just some problem in Ubuntu but it started to get really annoying and I finally became suspicious that it'd been using Intel graphics the whole time. Though GT 640M card is only mediocre, it should still be able to handle Left 4 Dead 2 even in the highest settings. So I tried to switch it back. (I bought my laptop for a thousand bucks three years ago, came with this video card, an Intel i7 quad-core CPU and a 1Tb 5400rpm hard drive. Good deal right? I even replaced the CD Drive with a 128Gb SSD so now I can dual-boot Windows and Ubuntu, awesome!)

I already did a similar thing before years ago but I was using bumblebee, which seemed not to be working on Ubuntu 16.04. I tried every method I found on stackoverflow but I kept running into this error when I launch nvidia-setting after installing nvidia-364 (sudo apt-get install nvidia-364):

** Message: PRIME: No offloading required. Abort
** Message: PRIME: is it supported? no

After an hour of struggling, I think I finally figured it out:

First, I removed bumblebee by running this command (since I had it installed):

sudo apt-get purge bumblebee*

Then I removed anything that had to do with Nvidia:

sudo apt-get purge nvidia-*

My final step was installing nvidia-364. (FYI, I rebooted the computer before doing this, just to be safe.)

sudo apt-add-repository ppa:graphics-drivers/ppa
apt-get update
sudo apt-get install nvidia-364

Inside it's already installed nvidia-settings and nvidia-prime, so if you follow my step and run nvidia-settings, you should see something like this, with all the list items and information and stuff, which means it's working.

Turned out I was only half right. The switching did fix the graphics of the game and the gameplay did become smoother, but it still froze sometimes.  which was because my home wifi sucks...




Kev