A dual core processor for a computer is a central processing unit (CPU) that has two separate cores on the same chip, each with its own cache. It is essentially two microprocessors in one. This type of CPU is widely available from many manufacturers. Other types of multi-core processors have also been developed, including quad-core processors with four cores each, hexa-core processors with six, octa-core processors with eight, and many processors with even more cores.
Dual core processor mounted on the motherboard.
In a traditional or single-core processor, the CPU receives sequences of instructions that it must sort, execute, and then selectively store in its cache for fast retrieval. When data is needed out of cache, it is retrieved over the system bus from random access memory (RAM) or storage devices. Accessing this reduces performance to the maximum speed allowed by the bus, RAM, or storage device, which is much slower than the speed of the CPU.
This situation is aggravated when the computer user performs multiple tasks. In this case, the processor must switch between two or more sets of data streams and programs. CPU resources are depleted and performance degrades.
In a dual-core processor, each core handles input data streams simultaneously to improve efficiency. Just as two heads are better than one, so are two hands. When one core is running, the other may be accessing the system bus or executing its own code.
To use a dual-core processor, the operating system must be capable of multithreading, and the software must have simultaneous multithreading (SMT) technology written into its code. SMT allows for parallel multithreading, where cores receive instructions from multiple threads in parallel. Without SMT, the software will only recognize one core. SMT is also used with multiprocessor systems common to servers.
A dual core processor is different from a multiprocessor system. In the latter, there are two separate CPUs with their own resources. In the first case, the resources are shared and the cores reside on the same chip. A multiprocessor system is faster than a dual core system, and a dual core system is faster than a single core system, all other things being equal.
An attractive value of dual-core processors is that they do not require new motherboards, but can be used on existing motherboards that have the correct sockets. For the average user, the difference in performance will be most noticeable when multitasking, until more software learns about SMT. Servers running multiple dual core processors will see a significant increase in performance.
