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.
More from Infra
- Ubicloud publishes "Fixing Tool-Call Accuracy in vLLM" — petrusenko_max · 2026-10-26
- Meta approves nonvoting Class C shares as 2026 capex guidance hits $135B–$145B — thione · 2026-10-26
- Unsloth Ships MiniMax-M3.1-Flash Quants: 2-bit Retains 91.5% Accuracy, Runs in 150GB RAM — danielhanchen · 2026-10-26
- Engineer with thousands of fabricated devices pours cold water on photonic crystal modulator yields — jwt0625 · 2026-10-26
- Anthropic S-1 reveals 48 cents of compute cost per dollar of Q2 revenue — nmasc_ · 2026-10-26
- Persistent AI joins UR network to route private AI inference with encrypted, IP-hidden traffic — 0xSammy · 2026-10-26