Nvidia’s evaluation of sixth-generation high-bandwidth memory (HBM4) has sparked a fierce contest among suppliers. ETNews reports that the company plans to finish testing HBM4 chips from SK Hynix, Samsung Electronics, and Micron by mid-November 2025, a decision that will determine who secures orders for Nvidia’s next-generation AI accelerator, Rubin, scheduled for launch in the second half of 2026.