What is a Dual Core Processor?

A dual core processor is a CPU with two separate cores on the same die, each with its own cache. It's the equivalent of getting two microprocessors in one. In a single-core or traditional processor the CPU is fed strings of instructions it must order, execute, then selectively store in its cache for quick retrieval. When data outside the cache is required, it is retrieved through the system bus from random access memory (RAM) or from storage devices. Accessing these slows down performance to the maximum speed the bus, RAM or storage device will allow, which is far slower than the speed of the CPU. The situation is compounded when multi-tasking. In this case the processor must switch back and forth between two or more sets of data streams and programs. CPU resources are depleted and performance suffers. In a dual core processor each core handles incoming data strings simultaneously to improve efficiency. Just as two heads are better than one, so are two hands. Now when one is ...  more

these "multi-cores" and wondered what they were. A multi-core processor means that the die, or the thing that holds the processor together, has not one processor as they often did before but usually two or four. What does this mean? Imagine having two horses pull a chariot as opposed to one. Let's get to some specifics: Clockspeeds: This is often referred to as the "megahertz" or "gigahertz". It is used primarily as a speed comparison among processors; for example, a processor of 500 mhz (megahertz) will run half as fast when compared to a processor of 1000 mhz or 1 ghz (gigahertz). Remember that all it does is refer to how many calculations the processor can handle and does not necessarily reflect the speed overall as other considerations need to be taken (RAM, for example). In a multi-core processor, measuring clockspeeds differ radically. Although a dual core processor of 2.4 ghz is better than a single core processor of 2.4 ghz, it's not exactly twice as fast. In fact, if you ...  more

To extend jerry's answer, even if a program isn't written to make use of more than one processor at a time, a dual-core processor will still be of benefit when running under a multi-tasking operating system such as Windows or Linux as the processes being run from more than one app running at a time (or even the OS internals) can be spread across both cores.  more