HBM3 (High Bandwidth Memory 3)

HBM3 achieves up to 819 GB/s per stack at 6.4 Gbps per pin by using through-silicon vias (TSVs) to vertically stack up to 12 DRAM dies in a single package, connected to the GPU via a silicon interposer. It offers 3× the bandwidth of GDDR6X at a fraction of the power. Used in AMD Instinct MI300X (192GB HBM3), NVIDIA H100 SXM5 (80GB HBM3), and Intel Gaudi 3 AI accelerators. The AMD Radeon RX 7900 XTX uses HBM2e. Not present in consumer gaming GPUs, which use GDDR6/6X.