> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solayer.org/llms.txt
> Use this file to discover all available pages before exploring further.
# RDMA & InfiniBand
**Remote Direct Memory Access (RDMA)** is a high-performance networking technology that enables **zero-copy data transfers** directly between application memory spaces across networked systems. By **bypassing the operating system (OS) networking stack**, RDMA eliminates **CPU overhead and context switches**, significantly reducing latency and improving throughput.
## RDMA Architecture & Mechanism
RDMA operates through **specialized network interface cards (RNICs)** that handle transport protocol processing and **direct memory operations in hardware**. Key features include:
* **Zero-Copy Data Transfers**: Applications can read/write remote memory **without CPU intervention**.
* **Bypassing Kernel Overhead**: Eliminates traditional network stack processing, reducing **latency to sub-microsecond levels**.
* **Explicit Memory Registration**: Memory regions must be **registered with the RNIC**, which maintains **virtual-to-physical address translation** for secure access.
RDMA supports **two transport modes**:
* **Reliable Connected (RC)**: Guarantees **in-order, reliable delivery** for critical workloads.
* **Unreliable Datagram (UD)**: Optimized for **low-latency applications** where minor packet loss is acceptable.
## InfiniBand: High-Performance RDMA Networking
**InfiniBand** is a widely adopted **RDMA-based networking architecture** designed for **high-performance computing (HPC)** and **data-intensive applications**. It provides:
* **Ultra-Low Latency**: Achieves **as low as 600 nanoseconds** end-to-end.
* **High Bandwidth**: Supports data rates from **10 Gb/s (SDR) to 100 Gb/s per port** over copper or optical fiber.
* **Host Channel Adapters (HCAs)**: Offload **protocol processing and memory translation** to hardware, reducing CPU load.
## RDMA & InfiniBand in Modern Computing
These technologies are critical for:
* **Distributed Machine Learning**: Efficient communication for **large-scale AI training workloads**.
* **HPC & Scientific Computing**: Accelerated **data sharing across compute clusters**.
* **Cloud Data Centers**: Optimized **storage access (NVMe-over-Fabrics)** and **disaggregated computing**.
With hardware acceleration and direct memory access, RDMA and InfiniBand deliver high-speed, low-latency networking suited for distributed blockchain workloads.