the amount of data that is being handled has almost increased as much as cpu speed and memory.
most 8bit computers only have a few kilobytes of video ram and only throw around a few thousand bytes to the screen a second, while running only one program at a time.
a modern computer with a 1280x1024 true color screen has to shift about 150 megs of data per second to scroll smoothly, all while running dozens of programs.
i think the main reason peoples computers seem slow though is they have too much crap running in the background adware, and viruses are bad enough but there are larger programs legitimate ones running in the background that the user my never actually use.
