Dual-core processors help computers distribute a workload more efficiency than single-core processors, which leads to better multitasking performance. Computers can also turn off unused processor cores to operate more efficiently.
As processors increase in speed, they generate more heat, and many processors can only run up to a certain speed before they become too hot to operate properly. Multi-core processors allow for greater performance by distributing their processing power across multiple cores. This also allows individual cores to operate at a lower speed when their full power isn't needed, which leads to better efficiency, less heat and an improved battery life.
Multi-core processors also allow devices to provide a smoother experience. Multi-core smartphones, for example, can reserve one processor for phone-related tasks. This ensures the phone can respond quickly to phone calls and other real-time events even if the other cores are busy.
However, not all applications are designed to take advantage of multiple processors. A program that runs on a single thread can only run on a single processor. Because of this, a system with a dual-core processor with 2.0GHz cores might not match the performance of a 4.0GHz processor. In most cases, processors can't access information on other processors without first storing it in the RAM or elsewhere.