NVLink 5.0 is NVIDIA's latest iteration of its ultra-high-speed interconnect technology, designed to enhance direct communication between multiple GPUs within a system. This technology is particularly crucial for GPU-intensive workloads such as AI training and high-performance computing. Here's how NVLink 5.0 handles data transfer between multiple GPUs:
Architecture and Bandwidth
NVLink 5.0 is built for the Blackwell architecture and offers a significant increase in bandwidth compared to its predecessors. Each Blackwell GPU supports up to 18 NVLink connections, with each link providing a bidirectional bandwidth of 100 GB/s. This results in a total bandwidth of 1.8 TB/s per GPU, which is twice that of the previous generation and more than 14 times the bandwidth of PCIe Gen5[1][2][4].
Direct GPU-to-GPU Communication
NVLink enables direct communication between GPUs without the need for a CPU intermediary, reducing latency and maximizing performance. This point-to-point connection architecture ensures that each GPU has a dedicated link to every other GPU, allowing for rapid data transfers without bandwidth sharing[7].
NVLink Switch for Scalability
The NVLink Switch chip plays a critical role in scaling NVLink connections across multiple GPUs, both within and between server racks. It facilitates all-to-all GPU communication at full NVLink speed, effectively turning a data center into a giant GPU. This setup supports up to 576 fully connected GPUs in a non-blocking compute fabric, enabling large-scale AI and HPC applications[1][2][4].
Collective Operations with SHARP
Each NVLink Switch includes engines for NVIDIA's Scalable Hierarchical Aggregation and Reduction Protocol (SHARP), which accelerates in-network reductions and multicast operations. This is essential for high-speed collective tasks in AI and HPC environments, allowing for efficient processing of large datasets and complex models[2][4].
Applications and Benefits
NVLink 5.0 is designed to support the development and deployment of trillion-parameter AI models and exascale computing applications. By providing high-speed, efficient communication between GPUs, it enables faster data exchange and processing, which is critical for complex computational tasks. This technology is integral to NVIDIA's data center solutions, offering unprecedented scalability and performance for AI and HPC platforms[1][2][4].
Citations:
[1] https://hardwarenation.com/resources/blog/nvidia-nvlink-5-0-accelerating-multi-gpu-communication/
[2] https://www.amax.com/fifth-generation-nvidia-nvlink/
[3] https://www.fibermall.com/blog/nvidia-nvlink.htm
[4] https://www.nvidia.com/en-us/data-center/nvlink/
[5] https://www.fs.com/blog/fs-an-overview-of-nvidia-nvlink-2899.html
[6] https://massedcompute.com/faq-answers/?question=How+does+NVLink+handle+data+transfer+between+GPUs+in+a+system+with+multiple+GPUs%3F
[7] https://www.amax.com/unleashing-next-level-gpu-performance-with-nvidia-nvlink/
[8] https://forums.developer.nvidia.com/t/nvlink-support-for-connecting-4-gpus/253975