GDDR6X / GDDR7 / HBM

The three main types of GPU memory. GDDR6X is the standard on current high-end consumer GPUs (RTX 4090), GDDR7 debuts on next-gen cards with higher bandwidth, and HBM (High Bandwidth Memory) is a stacked design used in data-center GPUs like the A100 and H100. For AI workloads, memory bandwidth directly affects tokens-per-second performance, so HBM cards are fastest but cost 10–20x more than consumer alternatives.