Glossary comparison
DMA vs RDMA: what is the difference?
The difference
Remote direct memory access moves data between the memories of two computers over a network. Ordinary DMA works within one system.
Direct memory access lets a device inside one computer move data to memory without the CPU. RDMA extends the idea across a network to another computer's memory.
The two terms
DMA
A mechanism where a dedicated engine transfers data between memory and peripherals or between memory regions without processor involvement, signalling completion by interrupt.
RDMA
Remote direct memory access (RDMA): a network technique that lets one computer read or write another's memory without involving the remote processor, giving low latency and low overhead.
Side by side
| Field | DMA | RDMA |
|---|---|---|
| Stands for | Direct Memory Access | Remote Direct Memory Access |
| Type | Acronym | Acronym |
| Domain | Design & Architecture | Compute & AI Hardware |
| Group | Memory and cache | Data centre systems |