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 finalizing the SPHBM4 memory standard, offering HBM4-class bandwidth with a narrow 512-bit interface to reduce integration costs and enable higher capacities by leveraging compatibility with organic substrates. While SPHBM4 aims to address limitations of HBM, it is not positioned to replace GDDR memory. The new standard maintains HBM4 performance with a 512-bit interface through serialization. SPHBM4 packages will use an industry-standard base die and standard HBM4 DRAM dies, potentially quadrupling memory capacity compared to HBM4. Despite potential cost benefits, SPHBM4 may not be a cost-effective replacement for GDDR7 due to the complexity and cost of its components.