JEDEC approves the GDDR5X memory type

The future of video memory is spelled High Bandwidth Memory (HBM), with features such as sky-high memory bandwidth, better energy efficiency and taking up less space on the graphics card. The downside is an expensive one interposer or “intermediate storage”, something that increases costs compared to, for example, GDDR5.

To get around the increased costs and at the same time offer higher bandwidth, Micron has developed GDDR5X, a further development of established GDDR5. The updated memory type is now adopted by the standardization body JEDEC, which very recently also nailed the specification for HBM2.

The big news in GDDR5X is doubling prefetch, from 32 to 64 bytes, at each memory access. This means a theoretical doubling in memory bandwidth at a given clock frequency compared to GDDR5. Initially, the memory type will be available at speeds between 10 and 14 Gbps, and in the long term, 16 Gbps is also expected to be possible. This compares to a maximum of 8 Gbps for GDDR5.

An advantage of GDDR5X over HBM is that the memory type works over the same memory controls as GDDR5, however, the laying on of hands is required to support the raised standard. This means that future graphics circuits with support for GDDR5X will also be able to use GDDR5, which can be used for AMD and Nvidia to produce budget-oriented graphics cards with the same circuit.

The memory type GDDR5X is expected to be found in graphics cards from AMD and Nvidia based on the architectures Polaris and Pascal respectively later in the year.