NVIDIA has revised the technical specifications for its upcoming Vera Rubin product line, impacting memory and interconnect performance. The company lowered the target speed for HBM4 memory from 11.7 Gbps per pin to 9.6 Gbps per pin. This adjustment results in a decrease in total memory bandwidth for the NVL72 rack-scale solution, which now stands at 1,400 TB/s compared to the previously announced 1,580 TB/s.
The interconnect capabilities also saw reductions, with NVLink bandwidth per GPU dropping from 1.8 TB/s to 1.5 TB/s. Consequently, the bidirectional NVLink bandwidth per GPU has been reduced from 3.6 TB/s to 3 TB/s. These changes follow a decision to lower the NVLink Nyquist frequency target from 56 GHz to 47 GHz, a move intended to improve manufacturing yields and system stability by reducing electrical demands on hardware components.
