India, Jan. 9 -- TrendForce's recent investigations indicate that Nvidia has revised the HBM4 specifications for its Rubin platform in 3Q25, raising the required per-pin speed to above 11 Gbps. This change has necessitated that the three major HBM suppliers modify their designs.

Furthermore, strong demand for Nvidia's previous-generation Blackwell products, driven by the ongoing AI boom, has prompted the company to adjust its mass-production timeline for the Rubin platform. Together, these factors have pushed back the ramp-up of HBM4, with mass production now expected to begin no earlier than the end of 1Q26.

TrendForce notes that SK hynix, Samsung, and Micron have all resubmitted HBM4 samples, and continue to refine their designs in re...