Grand Central Dispatch

A new technology in the upcoming (at this writing) Mac OS X 10.6 (“Snow Leopard”). Grand Central Dispatch (or “GCD”) helps software access and utilize multi-core processors more efficiently resulting in improved performance. With older approaches, individual applications handled their own multiple threads, which reduced efficiency and was more difficult for developers to program. With GCD, the operating system handles the threads for all compatible programs, automatically distributing tasks across all the available cores for best performance. GCD also manages threads that aren’t being used to recover system resources (some programs currently “allocate” threads to cores, even if the thread isn’t active).