With the introduction of multicore devices such as the iPad 2 and the quad-core Mac- Book Pro, writing multithreaded apps that take advantage of multiple cores on a device has become one of the biggest headaches for developers. Take, for instance, the introduction of iPad 2. On the launch day, only a few applications, basically those released by Apple, were able to take advantage of its multiple cores. Applications like Safari performed very well on the iPad 2 compared to the original iPad, but some third-party browsers did not perform as well as Safari. The reason behind this is that Apple has utilized Grand Central Dispatch (GCD).
