DMA (Direct Memory Access) Channels

The CPU is responsible for many tasks, including that of being a sort of “traffic cop,” overseeing the transfer of information between itself, memory, and various devices. Although a police officer on the corner of a busy intersection helps keep bumper-to-bumper rush-hour drivers on their best behavior, this manual stop-go-stop process isn’t the fastest way to get around town—or around the motherboard.

The expressway, beltway, or freeway that bypasses surface streets, traffic lights, and hand-signaling police officers is a faster way to travel when conditions are favorable. Similarly, bypassing the CPU for memory to add-on board transfers (either direction) is also a faster way to travel.