Daishin Securities says plans to mass produce lower stack HBM have effectively been called off, Jukan reports
Daishin Securities (Korea): Discussions on mass-producing lower-stack HBM (4-high/6-high) have effectively been called off. The shift from 12-high to 8-high has also been scaled back.
Context
If memory makers have dropped plans for cheaper, shorter HBM stacks, it signals AI chip buyers still want the tallest, highest capacity memory, which supports demand and pricing for SK hynix, Samsung and Micron.
High bandwidth memory, or HBM, stacks DRAM chips vertically next to AI processors, and taller stacks such as 12 high hold more memory. Reports earlier this year said Nvidia was weighing several memory configurations for future Rubin systems, including lower stack options. Counterpoint Research said in October that most Rubin products will likely use 12 layer HBM4, according to The Korea Herald.
Deep dive
On October 11, Jukan, who tracks Korean semiconductor research, posted a note attributed to Daishin Securities saying discussions on mass producing lower stack HBM, in 4 high and 6 high configurations, have effectively been called off. The note also said a planned shift from 12 high to 8 high stacks has been scaled back.
The claim comes only from Jukan's summary of the Daishin note. We could not find the Daishin report itself or independent coverage confirming it.
The note fits other recent reporting. The Korea Herald reported that Counterpoint Research expects most Nvidia Rubin products to use 12 layer HBM4 rather than the 8 layer configuration that had been rumored, calling concerns about slowing memory demand a misunderstanding. Nemothia reported that in August, Nvidia was said to be evaluating as many as four memory configurations for Rubin Ultra, including 8 layer options, because validation of taller stacks was unresolved.
Taller stacks cost more to make but deliver more capacity per processor, which matters for large AI models. Dropping lower stack plans would suggest customers are prioritizing capacity over cost, keeping supply of high end HBM tight.
What to expect next
Watch for confirmation from Daishin's full report, from memory makers such as SK hynix, Samsung and Micron on their earnings calls this month, and from Nvidia on the memory configurations for Rubin and Rubin Ultra.
Also watch HBM pricing and capacity plans, since a shift away from lower stacks would keep demand concentrated on the tallest and most profitable products.