Samsung and SK hynix race HBM capacity — yields up, still not enough cakes
Businesskorea reported on September 23 that Samsung plans to raise HBM wafer input from 180,000 to 250,000 sheets a month and to push HBM4-series chips toward about 80% of HBM shipments, with HBM4 yield reportedly up from under 60% to around 80%. SK hynix's Cheongju M15X input is described as rising from about 10,000 to 80,000 wafers a month, demand growth is put near 56% against supply growth near 50%, and HBM4 prices are seen about 65% higher next year.
What happened
On September 23, 2026, Businesskorea (Park Jung-hwan) reported that Samsung Electronics and are accelerating capacity expansion as AI data-center demand keeps outrunning supply. Samsung’s push, as the piece describes it, is to roughly double and HBM4E output next year versus this year, raise HBM wafer input from 180,000 sheets a month this year to 250,000 next year (about 40% more), and lift the HBM4-series share of total HBM shipments to about 80%.
The yield account matches an earlier Seoul Economic Daily report. HBM4 yield reportedly moved from below 60% in early mass production to around 80% recently. Businesskorea links that change to better profitability and a higher shipment volume. Treat the yield percentages as industry-source direction, the same caveat as in that earlier report. They are not a Samsung filing.
Share figures in the piece come via Counterpoint Research. Samsung’s HBM revenue share went from 21% in the first quarter to 33% in the second. SK hynix went from 58% to 50%. The gap narrowed from 37 percentage points to 17 in one quarter. Samsung’s pitch in the article is that memory, its own foundry, and advanced packaging sit in one company, including internal work on a 4-nanometre-class base die, as a path to contest HBM4 leadership. That is Samsung’s argument inside an industry story, not a customer teardown.
SK hynix’s answer is more factory space. Cheongju M15X wafer input is described as rising from about 10,000 sheets a month to 80,000. The Yongin cluster’s first fab is aimed at operations starting next year, and separate SK commentary carried by the piece puts the first cleanroom opening in early 2027. An analyst caution in the same article says a full Samsung supply ramp could soften some of the pricing power and high profitability SK hynix has enjoyed.
The balance Businesskorea cites for next year is demand growth of about 56%, above supply growth of about 50%. Major customers, including and , are putting more HBM on each next-generation accelerator, which tightens that balance further. The piece does not publish named contract volumes for either company. Its prevailing view is that HBM4 prices next year will be about 65% higher than this year. That price view is commentary in the article, not an investor-relations list.
Conventional memory is the spillover. Korean makers that prioritize HBM and server products leave less DRAM for PCs and smartphones. figures cited in the piece put the rise in conventional DRAM fixed contract prices at as much as 18% quarter on quarter in the third quarter. A side note in the same article says the Gen-5 DRAM platform is in mass production with a claimed productivity gain above 50% versus the prior generation, and that CXMT’s global DRAM revenue share was 10% in the second quarter, fourth in the world. That share is commodity DRAM, not an HBM ranking.
Why it matters
Who gets HBM still sets AI accelerator schedules more quietly than a performance slide. If Samsung’s yield holds and both Korean makers raise wafer input, buyers get a louder second source beside SK hynix. Businesskorea’s own math still has demand growth ahead of supply growth, so sellers can keep pricing power even while Samsung closes the share gap. PC and phone DRAM get tighter when wafers move into HBM. CXMT’s 10% DRAM share is the China commodity story running under Korea’s HBM buildout.
The new piece widens the earlier yield report into a capacity race and adds SK hynix’s M15X and Yongin figures. The yield band is the same industry-source range. Nvidia and AMD appear as major customers raising HBM per chip. The article stops there.
What to watch is whether the roughly 80% HBM4 yield band shows up in Samsung’s own quarterly comments; whether the 250,000-wafer Samsung guide and the 80,000-wafer M15X guide survive into 2027 spending talk; how the Counterpoint share gap moves after that 17-point spread; where HBM4 prices go against the roughly 65% view; and what conventional DRAM contract prices do if HBM keeps taking wafer starts.
The yield chapter this widens is Samsung HBM4 near 80%. The commodity DRAM note beside it is CXMT’s fifth-generation platform.