Industry preps new ‘cheap’ HBM4 memory spec with narrow interface, but it isn’t a GDDR killer — JEDEC’s new SPHBM4 spec weds HBM4 performance and lower costs to enable higher capacity

JEDEC is nearing completion of SPHBM4, a standard that enables full HBM4 bandwidth over a 512-bit interface using a 4:1 serialization, reusing standard HBM DRAM dies and a base die. The tech promises to enable a 2.5D integration on organic substrates to support up to 64 GB per stack and more stacks than HBM4 and HBM4E.