Nvidia forced to dial back key bandwidth targets on Vera Rubin hardware — tweaks will affect target specifications for memory and interconnect fabric

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• Nvidia has quietly cut Rubin’s listed HBM4 bandwidth from 22 TB/s to 19.2 TB/s per GPU and NVLink 6 from 3.6 TB/s to 3 TB/s
• The eight-GPU HGX Rubin NVL8 fares worst, losing 26% of its memory bandwidth and dropping from 2.3 TB to 2 TB of HBM4 capacity
• On paper, AMD’s MI455X now leads on per-GPU memory bandwidth and Helios on scale-up bandwidth, though neither side’s figures are benchmarked

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Nvidia has quietly lowered the memory and interconnect bandwidth it publishes for Vera Rubin, cutting per-GPU HBM4 bandwidth by about 13% and NVLink bandwidth by about 17%, without a press release or explanation.

The Vera Rubin NVL72 product page now rates each Rubin GPU at 19.2 TB/s of HBM4 bandwidth, down from 22 TB/s, and 3 TB/s of NVLink 6 bandwidth, down from 3.6 TB/s.

Memory capacity holds at 288 GB, and the headline 50 PFLOPS of sparse NVFP4 inference remains unchanged; however, at rack scale, aggregate memory bandwidth slips from 1,580 TB/s to 1,400 TB/s and the NVLink total from 260 TB/s to 216 TB/s, while the two-GPU Vera Rubin Superchip drops from 44 TB/s to 38.5 TB/s.

An edit without an announcement?

The revision surfaced in a report from IT Home, which compared Nvidia’s October documentation with a copy saved in June 2026. Wccftech then narrowed the window with Wayback Machine snapshots, placing the edit between September 1 and…