Almost all processors available today from Intel and AMD are either dual core or quad core. Which processor is best for your needs depends on what applications you use and the benchmarks associated with them.
Productivity
In most productivity benchmarks, quad core processors have a slight but largely unnoticeable advantage over dual core processors. Programs like Microsoft Word don't use much processing power and therefore don't benefit much from additional processing cores.
Gaming
Performance in gaming benchmarks is something of a toss-up between dual core and quad core processors. Many modern games make good use of quad cores and this results in better performance, but there are still some that don't use more than two cores effectively.
3D Rendering
In 3D rendering benchmarks, quad core processors are anywhere from 20 to 50 percent faster than dual core processors. Any professional who has to render 3D objects and animations should absolutely be using a quad core processor.
Video Editing and Decryption
As with 3D rendering, quad cores offer increased productivity between 20 and 50 percent when used with video editing software. This is a must for those who work with digital video for a living, but it is also useful for those ripping DVDs to a home theater computer.
Relative Value
Quad cores and dual cores are roughly even in terms of performance per dollar. However, the fastest processors in absolute terms are now quad cores, so those looking to spend more than $200 will be buying a quad core processor.
Tags: quad core, core processors, dual core, quad core processors, quad cores