Finally we come to home theater computers. These are literally PCs built for the home theater, and so their processor is the same as any desktop PC.
With that said, HTPCs tend to use relatively low-power processors. Intel Core i3, Pentium and Celeron brand processors are not uncommon. Modern HTPCs with an AMD processor will usually use an Athlon or Athlon II processor.
The processors in home theater computers are dramatically faster than those found in any other home theater device. However, the need to maintain an operating system – Windows, OS X or Linux – saps much of their performance advantage. Despite this, HTPCs are typically capable of displaying HD at 1080p without issue.