AMD MI455X Puts 432GB of HBM4 Into Its Next AI Accelerator

TechPowerUp reports that AMD launched its Instinct MI400 series and CDNA 5 architecture at Advancing AI 2026. The compact payload says the flagship MI455X uses a multi-chiplet design on a 2nm node and includes 432GB of HBM4. AMD also introduced Helios as a rack-scale AI platform. For RamTrend, the HBM4 capacity is the core signal. Accelerator vendors are moving to much larger memory pools per GPU as model context, training, and inference workloads expand. If MI455X ships at scale, it adds another major demand source for HBM4 supply alongside Nvidia and other AI accelerator programs.