NVLink 5.0 and NVLink 4.0 are both high-speed interconnect technologies developed by NVIDIA for facilitating communication between GPUs and other components within a system. However, they differ significantly in terms of bandwidth, signaling rate, and overall performance.
Bandwidth and Signaling Rate
- NVLink 5.0 offers a significantly higher bandwidth compared to its predecessor. It provides a total bi-directional bandwidth of 1.8 TB/s, which is nearly double the 900 GB/s bandwidth of NVLink 4.0[1][7]. This increase is due to a higher signaling rate of 100 GT/s, compared to 50 GT/s in NVLink 4.0[7]. Each link in NVLink 5.0 supports 50 GB/s in each direction, totaling 100 GB/s per link, which is twice the bandwidth per link of NVLink 4.0[1][7].
- NVLink 4.0 achieves a bandwidth of up to 900 GB/s with 18 links per GPU, each supporting 25 GB/s per direction (50 GB/s bidirectional)[7]. The signaling rate for NVLink 4.0 is 50 GT/s[7].
Architecture and Compatibility
- NVLink 5.0 is designed for the Blackwell architecture, which includes GPUs like those in the latest NVIDIA systems. It is optimized for high-performance computing (HPC) and AI applications, requiring direct GPU-to-GPU communication with minimal latency[1].
- NVLink 4.0 is used in systems like the Hopper architecture, which also supports high-performance applications but with slightly lower bandwidth compared to NVLink 5.0. It is compatible with NVIDIA's H100 GPUs and other similar models[7].
Use Cases
Both NVLink 5.0 and NVLink 4.0 are ideal for applications requiring high bandwidth and low latency, such as AI, deep learning, and HPC environments. However, NVLink 5.0's increased bandwidth makes it more suitable for the most demanding tasks where data transfer speed is critical.
Scalability and Performance
- NVLink 5.0 enhances scalability by providing more bandwidth, which is crucial for complex multi-GPU configurations. This allows for more efficient data transfer and processing in large-scale computing environments.
- NVLink 4.0 also supports scalable configurations but with less bandwidth compared to NVLink 5.0. It is still highly effective for demanding applications but may not match the performance of NVLink 5.0 in extremely high-bandwidth scenarios.
In summary, NVLink 5.0 offers superior bandwidth and signaling rates compared to NVLink 4.0, making it more suitable for the most demanding HPC and AI applications.
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.runpod.io/ai-faq/what-are-the-key-differences-between-nvlink-and-pcie
[4] https://hc34.hotchips.org/assets/program/conference/day2/Network%20and%20Switches/NVSwitch%20HotChips%202022%20r5.pdf
[5] https://en.wikichip.org/wiki/nvidia/nvlink
[6] https://massedcompute.com/faq-answers/?question=What+are+the+key+differences+between+NVLink+4.0+and+PCIe+5.0%3F
[7] https://en.wikipedia.org/wiki/NVLink
[8] https://www.fibermall.com/blog/what-is-nvidia-nvlink.htm