Advantages of direct memory access (DMA) in OS
Direct memory access (DMA) is a technology that is used by computers to increase speed and efficiency by allowing input-output devices to access RAM directly without involving the CPU. Before the use of DMA, computers used to fully involve the processor in the whole process of sending and receiving data from input and output devices. It started with programmed input/output and then interrupt and then later DMA.
When using programmed input/output, the processor sends the request to the input/output module to transfer data and then keeps checking if the transfer is done. This keeps the CPU busy checking whether the transfer is done. This reduces the overall performance of the computer.(more…)