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| network_stuff:machine_learning:networking:ai:infiniband [2026/02/01 15:22] – created jotasandoku | network_stuff:machine_learning:networking:ai:infiniband [2026/02/01 15:25] (current) – jotasandoku |
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| __**INFINIBAND**__: | __**INFINIBAND**__: |
| \\ | **InfiniBand** is a key technology for AI workloads, widely used in high-performance computing (HPC) and AI clusters for its **ultra-low latency**, **high throughput**, and **lossless performance**. It plays a crucial role in enabling efficient communication between nodes, especially for distributed machine learning tasks where large amounts of data need to be shared rapidly across many devices. |
| {{ :network_stuff:infiniband_technical_guide_for_network_engineers.pdf |}} | |
| | Key characteristics of **InfiniBand** in AI networking: |
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| | * **Low Latency**: InfiniBand offers **latencies as low as 1-2 microseconds**, which is critical for AI workloads that require predictable performance across nodes. |
| | * **High Bandwidth**: Supports **bandwidths of up to 400 Gbps** per link (with InfiniBand HDR), allowing the transfer of massive datasets needed in AI model training. |
| | * **Lossless Transmission**: InfiniBand is inherently lossless, ensuring that there is no packet loss during communication, which is essential for **AI workloads that cannot tolerate retransmissions** (e.g., when training deep learning models). |
| | * **Remote Direct Memory Access (RDMA)**: One of the most important features of InfiniBand, RDMA allows **direct memory-to-memory transfers** between nodes **without involving the CPU**. This is crucial in reducing CPU overhead and accelerating data transfers, making it ideal for AI training where rapid data sharing is required between nodes. |
| | * **Self-Healing**: InfiniBand has **built-in self-healing capabilities**, which means that in the event of a failure or congestion in a link, it can reroute traffic dynamically to ensure continuous operation. |
| | * **Queue Pair Communication**: InfiniBand uses **Queue Pairs (QP)**, consisting of a send queue and a receive queue, for managing communication between nodes. |
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| | Key operations managed by **InfiniBand Verbs** (the API for data transfer operations): |
| | * **Send/Receive**: For transmitting and receiving data. |
| | * **RDMA Read/Write**: To access remote memory directly. |
| | * **Atomic Operations**: Used for updating remote memory with atomicity, ensuring no race conditions in distributed systems. |
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| | Common InfiniBand verbs include: |
| | * ''ibv_post_send'': This verb is used to post a send request to a Queue Pair (QP). It initiates the process of sending data from the local queue to a remote queue. |
| | * ''ibv_post_recv'': This verb posts a receive request to a Queue Pair (QP). It prepares the local queue to receive incoming data from a remote queue. |
| | * ''ibv_reg_mr'': This verb registers a memory region (MR) for RDMA access. It allows the application to specify a memory buffer that can be accessed directly by the InfiniBand hardware for data transfer operations. |
| | * ''ibv_modify_qp'': This verb modifies the state of a Queue Pair (QP). It is used to transition the QP through various states, such as initiating a connection or resetting the QP. |
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| | InfiniBand is often deployed in **AI training clusters** where large-scale model training requires seamless, high-speed communication between GPUs across different servers. This makes it a popular choice in supercomputing environments and AI data centers. |
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| From [[https://en.wikipedia.org/wiki/InfiniBand|wikipedia]]: InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency.[..]. InfiniBand provides remote direct memory access (RDMA) capabilities for low CPU overhead. More info [[https://network.nvidia.com/related-docs/whitepapers/InfiniBandFAQ_FQ_100.pd|here]] | From [[https://en.wikipedia.org/wiki/InfiniBand|wikipedia]]: InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency.[..]. InfiniBand provides remote direct memory access (RDMA) capabilities for low CPU overhead. More info [[https://network.nvidia.com/related-docs/whitepapers/InfiniBandFAQ_FQ_100.pd|here]] |
