2048 bits per stack
HBM memory is getting faster with each generation, but HBM4 could bring radical improvements in data transfer speeds.
According to the latest information, the memory bus width can be doubled at once: from 1024 to 2048 bits per stack. For comparison: HBM became a 1024-bit bus back in 2015 and has not changed since then.
What if the GeForce RTX 4090 had such a memory?
That is, the peak throughput of the stack, all other things being equal, will increase from 1.15 to 2.3 TB/s. True, with such an impressive increase in throughput, manufacturers of finished devices may well reduce the number of stacks to save money, so a particular product may not receive this entire twofold increase.
Samsung and SK Hynix are already developing new memory, but there is no data yet on when it might hit the market. A document leaked online about six months ago indicated that HBM4 could only be released in 2026.
