Ubuntu 14.04 has visual artifacts and freezes

Solution 1:

Your screenshot is displaying repeating patterns of video artifacts which are characteristic of video RAM artifacts. If the RAM in your graphics card is failing, sometimes just a small fraction of the RAM goes bad while the rest of the RAM continues to work properly. This can result in a screen that looks like a fraction of the screen has glitchy, repeating patterns of video artifacts, while the rest of the screen is rendered properly.

In order to further diagnose and possibly solve the problem:

1. Check for a missing proprietary graphics card driver. Open the terminal and type:

   ubuntu-drivers devices
   

   This command will identify the recommended proprietary graphics driver from the default Ubuntu repositories.

2. Test if the visual artifacts also occur in situations that require a lot of video RAM, for example while browsing and playing a YouTube video in Firefox.

3. If your graphics card is removeable, temporarily remove it in order to check if the graphics card is causing the glitchy, repeating patterns of visual artifacts. Graphics cards that are intended more for ordinary day-to-day use than for gaming are relatively cheap to replace.

4. Read the answer to this question: What causes this graphical glitch in my web browser? which has a screenshot with a graphical glitch that looks similar to yours.