HBM Orders Exceed 2x Supply: NVIDIA Weighs 8-High HBM4 While CXMT Readies HBM3E at 20–30% Yields
HBM Orders Exceed 2x Supply: NVIDIA Weighs 8-High HBM4 While CXMT Readies HBM3E at 20–30% Yields
📌 The HBM Squeeze at a Glance
Card 1: SK hynix's own call statement. Cards 2–3: press reports and unnamed sources, unconfirmed by the companies. 1.5x is die arithmetic (12 ÷ 8), not an output forecast.
Yesterday we covered the numbers; today, what the HBM shortage is doing to the product itself. On its Oct 28 call, SK hynix said customer HBM requests are more than double what it can supply and that its DRAM and HBM volumes are "effectively sold out" through 2029. In the same week, reports said NVIDIA is weighing 8-high HBM4 stacks for Rubin Ultra instead of the 12-high HBM4E it originally planned. Reuters also reported that China's CXMT will start HBM3E production with only about 20–30% of chips usable. Samsung's 10:00 KST call today is the next test.
1. What Happened: The Reported Facts
Reported FactsSK hynix (call commentary, Oct 28): According to Hankyung and Korea JoongAng Daily, the company said customer HBM requests exceed twice its available supply. It also said long-term agreements (LTAs) and demand already under discussion leave its DRAM and HBM volumes effectively sold out for the three years through 2029. LTAs now cover 14 major customers, up from 10 a quarter earlier, and more than half of 2027 and 2028 capacity. SK hynix expects HBM4 to overtake HBM3E in both bit shipments and revenue in Q4, and it sent HBM4E samples to customers in Q2.
Reported FactsNVIDIA's stack-height rethink: ZDNet, as summarized by TrendForce on Oct 27, reported that Samsung and SK hynix are preparing to ship 8-high HBM4 for Rubin Ultra in Q2 2027. That would be a departure from the original 12-high HBM4E plan. Both suppliers have completed NVIDIA's qualification for 12-high HBM4, but 8-high parts need separate certification. Newspim (Oct 28) quoted SK hynix's call: some customers are "lowering stack counts to increase the number of cubes they can secure," which the company called a sign that demand is overwhelming supply.
Reported FactsCXMT enters HBM3E: Reuters (Oct 28) reported that China's largest DRAM maker has sampled HBM3E to domestic AI-chip designers and expects limited production within about two months. That is despite yields of roughly 20–30%, compared with about 70% at SK hynix, according to two unnamed sources. One source said its performance tested closer to SK hynix's older HBM3.
Chart: (A) Q2 2026 global HBM revenue share, Counterpoint Research via Reuters; (B) reported HBM yields, two unnamed sources via Reuters (unconfirmed); (C) our illustrative die arithmetic for 12-high vs 8-high stacks. Sources dated Oct 28, 2026.
2. The HBM Supplier Matrix
Reported data points only; a dash means no reliable public figure.
| Supplier | HBM revenue share, Q2'26 | Latest HBM disclosed | 12-Hi HBM4 for NVIDIA | 8-Hi HBM4 for Rubin Ultra | Reported yield |
|---|---|---|---|---|---|
| SK hynix | 50% | HBM4 (HBM4E sampled Q2) | Qualified | Preparing, Q2 2027 (reported) | ~70% (sources) |
| Samsung Electronics | 33% | HBM4 (HBM4E sampled) | Qualified | Preparing, Q2 2027 (reported) | — |
| Micron | 18% | HBM4 (>11 Gbps disclosed) | — | Not named in reports | — |
| CXMT | — (10% of DRAM revenue) | HBM3E sampling; limited output in ~2 months | No | No | ~20–30% (sources) |
Sources: Counterpoint Research via Reuters (shares; they sum to 101% because of rounding; CXMT's DRAM share); Reuters (CXMT status, yields, Samsung's July HBM4E sampling); SK hynix call via Korea JoongAng Daily (HBM4E samples); ZDNet via TrendForce (qualification, 8-high plans, Micron speed). All dated Oct 27–28, 2026.
Reported FactsThe economics of going shorter: Newspim notes that moving from 12 to 8 layers theoretically yields 1.5x as many stacks from the same number of DRAM dies. It also cites industry expectations that 8-high parts will cost 10–20% more per unit of capacity. SK hynix argued on its call that higher capacity per die in HBM4E would offset much of the loss from fewer layers. Separately, Wccftech (via TrendForce) reported that NVIDIA trimmed Rubin GPU HBM4 bandwidth from 22 TB/s to 19.2 TB/s, roughly 13%. IT Home, cited by TrendForce, says this could let more HBM4 parts qualify. Not every outlet agrees on how big the shift is. DIGITIMES (Oct 15) reported that standard Rubin will still rely mostly on 12-high HBM4.
💡 Market Analyst Takeaway
AnalysisWhen the largest buyer accepts less memory per stack, and reportedly pays more per gigabyte, to get more stacks, it is a strong sign that the supplier side has pricing power. For SK hynix and Samsung, 8-high HBM4 is less a downgrade than a product that is easier to yield. Taller stacks are harder to build, so a shorter stack could raise sellable output from the same TSV and packaging lines. That is our inference; neither company has disclosed 8-high yields or margins.
AnalysisCXMT's decision to ship at 20–30% yields looks more like a response to China's supply gap under US export controls than a near-term threat to Korean share outside China. The medium-term risk is learning speed: each production lot improves yields. Investors should watch whether CXMT's yields climb toward the level of its conventional DRAM over 2027.
3. What to Watch Next
- Samsung, today at 10:00 KST: Samsung Electronics holds its 3Q26 earnings call after Oct 8 guidance of about ₩195T in revenue and ₩107.4T in operating profit (Samsung Newsroom). Newsis reported that Samsung said in Q2 it aims to run 60–70% of memory capacity under LTAs. Today's call is the first chance to hear Samsung's view on 8-high HBM4, HBM4 volumes and a roughly ₩30T cash dividend plan. Divisional figures were not yet public when this was written.
- Market tone: On Oct 28, SK hynix closed up 10.89% at ₩1,487,000 and Samsung up 9.01% at ₩242,000, while the KOSPI rose 6.63% to 6,012.44 (Korea JoongAng Daily).
- China demand: Local media reported that Alibaba, Tencent and ByteDance are seeking long-term server-memory deals with Samsung and SK hynix (via Korea JoongAng Daily). Unconfirmed by either company.
- Pricing projections (third-party): TrendForce expects conventional DRAM contract prices to rise another 10–15% QoQ in Q4 after an estimated 13–18% in Q3 (via Yonhap). J.P. Morgan analysis cited by Benzinga sees an HBM supply shortfall of 20% in 2026, 19% in 2027 and 16% in 2028. These are estimates, not guidance.
Related coverage: SK hynix's Q3 beat and ₩100T return plan, NVIDIA's $279B supply commitments and Vera Rubin HBM4 demand, and China's memory expansion matrix (CXMT and YMTC).
Check the Primary Sources
Earnings materials and call replays are on the companies' official investor relations sites.
🔍 SK hynix Official IR: 3Q26 Results & Call 🔍 Samsung Electronics Official IR: 3Q26 Call (Oct 29, 10:00 KST)
Comments
Post a Comment