AMD and SK Hynix announced they will jointly develop high-bandwidth 3D stacked memory technology. AMD may use this memory for future graphics cards and perhaps even APUs. 3D stacked memory promises to be not only smaller but also faster than GDDR5.
3D stacked memory should be used as high-bandwidth memory (HBM) that’s smaller yet faster than GDDR5. It can be used as system RAM or graphics memory. HBM was developed mainly for graphics applications and it should enter mass production in 2015. Built using new Wide I/O and TSV technologies, it should support bandwidths from 128GB/s to 256GB/s.
Such bandwidth makes a lot more sense when it comes to GPUs, at least at this point. Both Nvidia and AMD are expected to use stacked memory in their 20nm products, but probably not in first-generation 20nm products.