NVL72's Steep Bandwidth Cliff Inside and Outside the Rack
AccBalanced · x · 2026-07-17
The post highlights the communication disparity between the inside and outside of the NVIDIA NVL72 rack:
- GPUs inside the rack can interconnect via NVLink at approximately 1.8 TB/s;
- Once traffic leaves the rack, network card bandwidth drops to around 50 GB/s;
- This roughly 18 to 36x bandwidth gap explains a portion of NVIDIA's pricing power.
The author concludes that chips only make up half the product; the true product includes rack-level interconnects and system design.
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