DMA suitability — choosing endpoints Direct Memory Access (DMA) is particularly well-suited for high-throughput transfers between which pair of system components?

Introduction / Context:
DMA offloads block data transfers from the CPU by allowing a controller to move data directly between peripherals and memory. This boosts throughput and frees CPU cycles for computation rather than byte-by-byte copying.

Given Data / Assumptions:

• Typical system includes mass storage (disk), RAM, and a DMA controller.
• Goal: rapid, large transfers with minimal CPU intervention.

Concept / Approach:
DMA is most beneficial when a peripheral must move large data blocks into or out of main memory. Storage devices (like disks) commonly use DMA to stream sectors to RAM buffers. The CPU sets up the transfer descriptors and is interrupted upon completion.

Step-by-Step Solution:
Identify high-volume path → disk ↔ RAM.DMA controller arbitrates bus, performs bursts.CPU overhead minimized → improved system performance.

Verification / Alternative check:
Operating systems and drivers routinely configure DMA for disk, network, and multimedia devices to move data to/from RAM without CPU copying.

Why Other Options Are Wrong:

• Disk ↔ CPU: defeats DMA’s purpose; CPU would be in the data path.
• Disk ↔ ROM: ROM is not a standard destination for runtime data streams.
• Disk ↔ I/O: vague; ultimate destination for bulk data is usually RAM for processing.

Common Pitfalls:
Ignoring cache coherency or alignment in DMA buffers; mishandling memory protection when mapping DMA regions.

Final Answer:
disk drive and RAM