The final specification of HBM4 is taking shape

For now, however, there is only a draft, which JEDEC shared.

JEDEC is close to finalizing the HBM4 specification, which could be a major step forward in the server accelerator market. According to current data, 4Hi, 8Hi, 12Hi and 16Hi category memory stacks can be created, and the maximum capacity can be 32 gigabits per chip. This would result in a 64GB stack in the peak configuration.

The above parameters can already be obtained with HBM3, but HBM4 will offer twice as many channels projected onto a stack, so the planned speed of 6.4 Gbps will mean doubled memory bandwidth.

JEDEC is working on making the same memory controller capable of supporting HBM3 and HBM4 at the same time in order to make the transition easy.