What Is NVLink? NVIDIA's High-Speed GPU Interconnect Explained.

What Is NVLink?

NVLink is NVIDIA's high-speed interconnect technology designed to exchange information between compatible computing processors, particularly GPUs.

It helps multiple processors communicate efficiently during demanding computing workloads.

NVLink is important in AI infrastructure because training and running large models can require substantial communication between GPUs.

For example, a data center training a robotics foundation model across multiple GPUs may use NVLink to exchange intermediate calculations and model-related information.

Key Takeaways

• NVLink provides high-bandwidth communication between supported NVIDIA computing devices.
• It is particularly useful when AI workloads require frequent information exchange across multiple GPUs.
• NVLink capabilities depend on hardware generation and system architecture.

How Does NVLink Work?

Imagine a server containing several GPUs.

A large AI model may be distributed across those processors because one GPU does not have sufficient memory or computing capacity for the workload.

The GPUs need to exchange information during execution.

Without efficient connections, communication can become a bottleneck.

NVLink provides dedicated high-speed links between compatible devices.

Supported systems can use these links to move information more efficiently than would be possible through some conventional peripheral communication paths.

The available bandwidth and supported connections depend on the NVLink generation.

NVLink vs. PCIe

PCI Express, or PCIe, is a general-purpose interconnect commonly used for GPUs, storage devices, and other computer components.

NVLink is designed for high-performance communication between compatible NVIDIA processors.

For example, a GPU may communicate with the host computer through PCIe while also using NVLink to exchange information with other GPUs.

The technologies can therefore work together.

NVLink does not replace every function of PCIe.

What Is NVLink Switch?

NVLink Switch extends NVLink connectivity across larger groups of supported GPUs.

It uses switching technology to create communication paths between processors.

For example, NVIDIA's large GPU systems use NVLink Switch arrangements to support extensive GPU-to-GPU communication.

This can make it more practical to distribute demanding AI workloads across multiple accelerators.

However, system performance still depends on the application and how efficiently it distributes computation.

Why Does NVLink Matter for Physical AI?

Many robotics companies train AI models using data center infrastructure.

Those models may require substantial GPU resources.

High-speed interconnects can improve the efficiency of distributed training and certain large-scale inference workloads.

The deployed robot itself generally does not require NVLink unless its computing architecture specifically supports and benefits from it.

Frequently Asked Questions

Does NVLink combine several GPUs into one physical processor?

No. It connects separate computing devices. Software must still manage how workloads and information are distributed.

Does every NVIDIA GPU support NVLink?

No. Support varies by product family and generation.

The Bottom Line

NVLink helps NVIDIA computing systems exchange information across compatible processors. Its importance to Physical AI comes primarily from supporting the large computing infrastructure used to develop demanding AI models.