Which one of the following facilitates transfer of bulk data from hard disk to main memory with the highest throughput?
Show Hint
- DMA based I/O transfer
- Interrupt driven I/O transfer
- Polling based I/O transfer
- Programmed I/O transfer
The Correct Option is A
Solution and Explanation
- DMA (Direct Memory Access) based I/O transfer: This method allows peripherals (like a hard disk) to directly access the system's memory without involving the CPU for every byte of data. This dramatically improves data transfer rates, as the CPU is not bogged down with the task of moving data between memory and peripherals. DMA is typically used for high-speed data transfer like bulk data from a hard disk to memory, offering the highest throughput.
- Interrupt-driven I/O transfer: In this method, the CPU is notified via an interrupt when the I/O device is ready to send or receive data. While efficient, it still requires the CPU to manage the data transfer, which can reduce throughput compared to DMA.
- Polling-based I/O transfer: This involves the CPU regularly checking (polling) if the I/O device is ready for data transfer. This method is less efficient because the CPU wastes cycles checking for availability, reducing overall throughput.
- Programmed I/O transfer: This is the most basic form of I/O where the CPU directly controls the data transfer, typically using simple instructions to move data between memory and devices. This method is slow because the CPU is involved in every step of the process.
Therefore, DMA offers the highest throughput and is the correct answer.
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