The fifth-generation NVLink, introduced in 2024, marks a significant advancement over its predecessors, particularly in terms of bandwidth and scalability. Here are the key differences between NVLink 5.0 and previous generations:
Bandwidth and Speed
- NVLink 5.0 offers a substantial increase in bandwidth, providing 1.8 TB/s of total bidirectional bandwidth per GPU. This is achieved through 18 NVLink links, each capable of 50 GB/s in each direction, totaling 100 GB/s per link bidirectionally[1][4].- NVLink 4.0, found in Hopper GPUs, supports 18 links as well but at a lower speed of 50 GB/s per link, resulting in a total bandwidth of 900 GB/s[7].
- NVLink 3.0, used in Ampere GPUs like the A100, supports up to 12 links with a bandwidth of 50 GB/s per link, achieving a total of 600 GB/s[7].
Scalability and Architecture
- NVLink 5.0 is designed for the Blackwell architecture, which is optimized for multi-GPU systems. It enables seamless communication between hundreds of GPUs, making it ideal for exascale computing and large AI models[1][4].- Previous generations, while also supporting multi-GPU configurations, did not offer the same level of scalability as NVLink 5.0. For example, NVLink 4.0 was used in Hopper GPUs, which also supported large-scale GPU configurations but with less bandwidth[7].
Technology and Interconnectivity
- NVLink 5.0 utilizes advanced PAM4 differential-pair signaling, similar to NVLink 4.0, but with higher data rates per lane[7].- NVLink Switches play a crucial role in NVLink 5.0, allowing for efficient all-to-all communication between GPUs. The NVLink 5 Switch offers 144 ports with a non-blocking switching capacity of 14.4 TB/s, significantly enhancing scalability across multiple servers[4].
Applications and Performance
- NVLink 5.0 is optimized for high-performance computing applications, particularly those involving large AI models and exascale computing. Its increased bandwidth allows for faster data exchange between GPUs, which is critical for complex AI and deep learning tasks[1][4].- Previous generations were also focused on high-performance applications but were limited by their lower bandwidth. NVLink 3.0 and 4.0 were used in environments requiring high computational power, such as AI and HPC, but with less capacity for very large models compared to NVLink 5.0[2][7].
Overall, NVLink 5.0 represents a significant leap forward in terms of bandwidth, scalability, and performance, positioning it as a critical component for future advancements in AI and high-performance computing.
Citations:
[1] https://hardwarenation.com/resources/blog/nvidia-nvlink-5-0-accelerating-multi-gpu-communication/
[2] https://www.fibermall.com/blog/nvidia-nvlink.htm
[3] https://www.fibermall.com/blog/what-is-nvidia-nvlink.htm
[4] https://www.nvidia.com/en-us/data-center/nvlink/
[5] https://www.fibermall.com/blog/evolution-of-nvlink.htm
[6] https://www.nexgencloud.com/blog/performance-benchmarks/nvidia-blackwell-vs-nvidia-hopper-a-detailed-comparison
[7] https://en.wikipedia.org/wiki/NVLink
[8] https://www.naddod.com/blog/unveiling-the-evolution-of-nvlink