GPUs use dynamic RAM too (though discrete cards usually have GDDR rather than DDR, which gives higher bandwidth). The most fundamental difference between a CPU

GPUs use dynamic RAM too (though discrete cards usually have GDDR rather than DDR, which gives higher bandwidth). The most fundamental difference between a CPU and GPU isn't the memory hierarchy (modern GPUs are growing cache hierarchies as well) but the core architecture (vector/highly threaded "small cores", vs. out-of-order/superscalar "big cores").