Xvid runs very fast as it is optimized for the latest CPUs. Recording video from a camera in realtime or playing back HD video smoothly are not a problem. Your computer will still have plenty of power left for your other tasks!
The Xvid codec compresses video files to make them smaller. It can compress video at a ratio of 200:1 or more compared to uncompressed video. And Xvid can do this without visible quality loss and retaining a sharper picture than other codecs.
A big advantage of Xvid compressed video files is that they play almost anywhere. The Xvid software runs on many platforms and most popular video players support it. Also, home entertainment devices like TVs or DVD/BD players can handle Xvid video.