Processor

The CPU (central processing unit) is the brains of the computer. The performance of the processor, which is measured in megahertz (MHz) or gigahertz (GHz), determines how quickly the computer responds to the requirements placed on it and the higher the number, the faster the processor.
The two major players in the CPU market are Intel and AMD. While each have individual strengths and weaknesses, both companies offer processors with comparable levels of performance. Here's a breakdown of their offerings:
While it might be tempting to buy a PC with a 1.7 GHz Pentium 4 instead of a 1.4 GHz, it's not necessarily the most economical decision. The newest processor to hit the market usually does not have enough of a performance improvement over its predecessor to justify its high price. You can find a better deal by buying a couple of speeds below the leading edge.