GDDR6 Graphics DDR 6
High-speed RAM for consumer GPUs — wider bus and higher clock than ordinary DDR.
JEDEC spec, 2018. Pseudo-Open Drain signalling, PAM-3 (in the GDDR6X variant). Typically 14–24 Gbps per pin × 256–384-bit bus = 700–1000 GB/s total on an RTX 4080. The consumer cousin of the same principle as HBM, but cheaper per GB and not stacked. The RTX 50 series (2025) uses GDDR7. Data centre GPUs prefer HBM for raw width; consumer GPUs make do with GDDR.