I started using Ubuntu a very short time ago, and it was working perfectly! I upgraded to 12.04 yesterday, and today I realize that everything is running slow. For example, video streaming online, from sites such as Youtube is not working correctly, audio and video breaks constantly. I have a 64 bit system, with a Intel® Core™2 Duo, 2.10GHz × 2 . I don't know what more to add.
free -m on the terminal, it returned that I had only 524MB free from 3858MB. All that i have running at this point is Mozilla Firefox.