Samsung and SK Hynix to supply 8Hi HBM4 to NVIDIA's Rubin Ultra from 2027

On October 26, 2026, Korean outlet ZDNET Korea reported that Samsung Electronics and SK Hynix plan to begin mass production of 8Hi (eight-high) HBM4 memory stacks in the second quarter of 2027 and ship them to NVIDIA. According to the report, NVIDIA held serious discussions with both memory makers in Q3 2026 regarding 8Hi HBM supply. The shift in plan stems from NVIDIA's consideration of using 8Hi HBM4(E) in both Rubin Ultra and the standard Rubin platforms, with the goal of optimizing overall supply and performance.

At present, the two manufacturers are primarily producing 12Hi versions of HBM4, which offer larger capacity per stack. However, incorporating more DRAM dies raises the cost per unit of bandwidth, reduces the total number of stacks available, and higher stack counts also lead to lower yield rates. One report noted that thermal management and yield challenges are prompting Samsung Electronics and SK Hynix to adjust their HBM4 strategy, planning to significantly increase supply of 8-layer HBM4 memory for NVIDIA's next-generation AI accelerator, Rubin Ultra, starting from the second quarter of 2027, rather than pursuing the 12-layer stacking approach that was previously widely favored.

Additionally, NVIDIA has updated the specifications for HGX Vera Rubin NVL8 and HGX Rubin NVL8 to a combined 2TB of HBM4 per system, which corresponds to 8Hi 32GB HBM4 stacks. As of now, these plans remain based on media reports, with mass production scheduled for Q2 2027.