💡 The memory chips powering AI are dominated by just three companies from Korea and the U.S. Now a mysterious Japanese startup called SAIMEMORY has emerged with a radical idea: stack memory chips vertically instead of flat, aiming for 2-3x capacity, half the power consumption, and 60% lower manufacturing costs. Could Japan reclaim its position in the memory industry after four decades?
The "Mystery Memory Maker" Reveals Itself
On February 3, 2026, at Intel's "Intel Connection Japan 2026" event in Tokyo, a previously unknown company made its first public appearance. SAIMEMORY — a wholly owned subsidiary of SoftBank established in December 2024 and fully operational since June 2026 — stepped onto the global semiconductor stage.
The name "SAI" draws from the Japanese kanji for talent and genius (才). CEO Hideya Yamaguchi declared that the AI era represents a transformation surpassing previous industrial revolutions, and that SAIMEMORY intends to provide solutions for this new world.
While SoftBank is the parent company, the initiative has assembled a formidable coalition: Intel, the University of Tokyo, Fujitsu, RIKEN (Japan's flagship research institute), Shinko Electric Industries, and PowerChip Semiconductor Manufacturing.
AI's Biggest Bottleneck: The "Heat and Performance Wall" in Memory
Why does the world need new memory technology? The answer lies in the severe challenges facing AI data centers.
Training and running large-scale AI models requires processors to handle enormous volumes of data. Memory serves as the high-speed workspace for this data, and the current go-to solution is HBM (High Bandwidth Memory). But HBM has hit significant limitations.
The conventional approach stacks DRAM chips horizontally, layer upon layer. This creates a critical thermal problem: heat from lower layers gets trapped beneath upper layers. The current mainstream configuration of 16 layers is approaching its practical ceiling, with most experts estimating a maximum of around 20 layers before thermal constraints become insurmountable.
Beyond the technical challenges, the HBM market is effectively controlled by just three companies — SK Hynix, Samsung, and Micron. With AI demand surging, supply cannot keep up, and prices remain roughly six to seven times higher than standard DRAM. This market concentration creates both cost and supply chain vulnerabilities for the entire AI industry.
A Revolutionary "Vertical" Architecture: ZAM (Z-Angle Memory)
SAIMEMORY's next-generation memory, ZAM (Z-Angle Memory), takes a fundamentally different approach to these challenges.
Instead of stacking chips horizontally on a flat plane, ZAM arranges dies along the Z-axis — essentially standing them vertically. This world-first architecture allows heat from each die to dissipate evenly upward, directly addressing the thermal concentration that plagues conventional stacked memory.
"Memory development typically prioritizes high capacity and bandwidth," CEO Yamaguchi explained. "Our memory puts low power consumption first. That's what makes us different." The company has already achieved 16-layer vertical stacking in its current prototypes, with room for further expansion.
The performance targets for ZAM are ambitious:
- Capacity: 2-3x that of HBM (per unit area)
- Power consumption: Over 50% reduction compared to HBM
- Manufacturing cost: Up to 60% lower than HBM
- Bandwidth: Equal to or exceeding HBM
ZAM also leverages Intel's EMIB (Embedded Multi-Die Interconnect Bridge) technology to minimize latency between memory and AI processors, improving overall system efficiency.
Technology Rooted in U.S. National Labs
The technological foundation for ZAM comes from Intel's work under the Advanced Memory Technology (AMT) program, funded by the U.S. Department of Energy. This program, managed through Sandia National Laboratory, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory, validated next-generation DRAM stacking and bonding techniques through the Next Generation DRAM Bonding (NGDB) initiative.
Gwen Voskuilen, a principal member of technical staff at Sandia, expressed enthusiasm for the technology's potential to bring high-bandwidth memory to systems that previously could not adopt HBM due to capacity and power constraints.
For Intel, this collaboration marks its first serious return to the memory business since exiting the DRAM market in the 1980s — ironically, under pressure from Japanese competitors at the time. Now, decades later, Intel is partnering with a Japanese company to re-enter the very market it once left.
Development Timeline and Funding
SAIMEMORY has laid out the following roadmap:
- By FY2027 (ending March 2028): Complete prototype development (approximately ¥8 billion / ~$53 million investment)
- By FY2029: Achieve commercialization and establish mass production
SoftBank is contributing approximately ¥3 billion, while Fujitsu and RIKEN are investing around ¥1 billion combined. The remaining funding is expected to come through Japan's Ministry of Economy, Trade and Industry (METI) via NEDO, the national research and development agency.
This public-private framework mirrors the approach taken with Rapidus, another Japan-U.S. semiconductor collaboration leveraging IBM technology for advanced chip manufacturing — suggesting ZAM could evolve into a full-scale national project.
Reviving Japan's Memory Industry Legacy
In the 1980s, Japan dominated approximately 70% of the global DRAM market. The subsequent rise of Korean and Taiwanese manufacturers eroded that position, and the 2012 bankruptcy of Elpida Memory effectively ended Japan's presence as a major DRAM producer.
SAIMEMORY's ambition goes beyond launching a new product. It represents Japan's attempt to reclaim a strategic position in the semiconductor supply chain. Under METI's "AI and Semiconductor Industry Base Strengthening Framework," the government has planned over ¥10 trillion in public support through 2030, and SAIMEMORY is positioned as a key element of that strategy.
Challenges and Uncertainties
Healthy skepticism is warranted. SK Hynix, the current HBM leader, maintains a blistering pace of innovation, with HBM4 and beyond already in development. By the time SAIMEMORY completes its prototype in FY2027, competitors will have advanced further.
There are also geopolitical considerations. The U.S. government holds a 9.9% stake in Intel, making it the largest single shareholder. The Trump administration's "America First" manufacturing policies could pressure Intel to localize ZAM production in the United States rather than Japan, creating tension with the project's intended purpose of strengthening Japan's domestic semiconductor capabilities.
Additionally, the ¥8 billion development budget, while significant, is modest by semiconductor industry standards. Compared to Rapidus's multi-trillion-yen investment, SAIMEMORY may need to secure substantially more funding as the project progresses.
Conclusion: Can Japan Rewrite the Rules of Memory?
SAIMEMORY's ZAM technology directly confronts the triple challenge of power consumption, thermal management, and cost that constrains AI data center growth. By combining SoftBank's financial resources, Intel's cutting-edge technology, and the research capabilities of the University of Tokyo and RIKEN, this project embodies Japan's semiconductor revival ambitions.
If successful, ZAM could fundamentally alter the cost structure of global AI infrastructure. But fierce competition from Korean manufacturers, geopolitical complexities, and a tight development timeline present real obstacles.
In Japan, excitement about semiconductor resurgence is tempered by questions about feasibility. What's the conversation like in your country about memory technology and AI semiconductor development? We'd love to hear your perspective.
References
- https://www.saimemory.co.jp/news/press/20260203_01/
- https://pc.watch.impress.co.jp/docs/news/2083139.html
- https://www.softbank.jp/en/corp/news/press/sbkk/2026/20260203_01/
- https://eetimes.itmedia.co.jp/ee/articles/2602/03/news099.html
- https://eetimes.itmedia.co.jp/ee/articles/2602/03/news074.html
- https://www.cnbc.com/2026/02/03/softbank-subsidiary-saimemory-intel-ai-memory-z-angle-program.html
Reactions in Japan
The SAIMEMORY announcement genuinely moved me. As someone who remembers Japan's DRAM golden age in the '80s, seeing Japan challenge the world in memory again is deeply emotional. The technology looks sound too. Rooting for them.
Isn't this another SoftBank pipe dream? Masa Son's visions are always grand, but semiconductor manufacturing doesn't run on talk alone.
As a semiconductor engineer, ZAM's vertical stacking makes technical sense. The industry consensus is that conventional HBM thermal dissipation is hitting its limits. The real question is mass production yield rates — that'll be the key.
Isn't ¥8 billion way too little for the semiconductor world? Rapidus is working with trillions of yen. This will test how serious they really are.
Intel left the DRAM market because Japanese companies beat them. Now 40 years later, they're coming back by partnering with a Japanese firm. The historical irony is almost too much.
Read the Nikkei article. Halving power consumption is attractive, but isn't 2029 commercialization too late? SK Hynix will probably have HBM5 by then, and the competitive landscape will be completely different.
The power issue in data centers is genuinely severe. Considering how much electricity AI consumes with every query, developing low-power memory is a globally necessary initiative.
University of Tokyo, RIKEN, Fujitsu, Intel... the names are impressive, but I hope this doesn't become a 'too many cooks' situation.
Apparently Intel stock hit a 52-week high after the SAIMEMORY announcement. The market likes it. Though stock prices and actually completing the technology are two different things.
Geopolitically this is a fascinating move. The U.S. government is Intel's largest shareholder, and Japan's government is funding through NEDO. This is effectively a Japan-U.S. national project.
Memory might seem unglamorous, but it directly affects AI service pricing. If ZAM really achieves 60% cost reduction, subscription fees for services like ChatGPT could actually come down.
Having witnessed Elpida's downfall, I'm split 50-50 between hope and anxiety. In this industry, even good technology can vanish depending on management and market timing...
This could fall apart if the Trump administration demands 'make it in America.' If manufacturing gets pulled to the U.S., the whole point for Japan diminishes.
First Rapidus, now SAIMEMORY. Japan's semiconductor industry has really come alive these past few years. Plus there's the TSMC Kumamoto factory too.
I love how CEO Yamaguchi called this a 'catastrophic challenge.' That's what the semiconductor world is really about. You can't win by playing it safe.
There's no way SK Hynix and Samsung will just sit and watch. It'll come down to development speed. Bureaucratic decision-making won't cut it.
As a memory engineer, the vertical stacking concept itself isn't new. The real question is whether they can establish a reliable mass production process. That's where HBM manufacturers' true strength lies.
I work at an AI company and HBM costs are a real headache. If they truly achieve 60% cost reduction, it would be a game-changer for the entire industry. Rooting for them.
As a Korean, I have mixed feelings. This could threaten SK Hynix and Samsung, but competition drives progress. That said, I think the 2029 timeline is overly optimistic.
As a semiconductor researcher in Germany, the fact that this is based on technology validated at U.S. DOE national labs is reassuring. If Sandia's name is attached, the technical foundation is solid.
From a data center operations perspective, 50% power reduction is revolutionary both for electricity costs and cooling infrastructure. We feel HBM's power issues every single day.
Interesting move, but isn't this ultimately dependent on Intel's technology? SoftBank just provides money — it's unclear how much independent memory design capability exists on the Japanese side.
Intel stock surging says it all. Investors view the re-entry into memory positively. Whether it's profitable long-term is another matter entirely.
From an environmental perspective, AI's energy consumption is reaching unsustainable levels. Low-power memory development is both a technical challenge and a climate action.
From China's perspective, the deepening Japan-U.S. semiconductor cooperation is concerning. Memory is directly tied to national security, and China needs to accelerate its own memory development through companies like CXMT.
Knowing Intel's 1980s DRAM exit history makes this deeply poignant. They left the market after losing to Japan, and now they're returning by partnering with Japan.
For Indian AI startups, cheaper memory would be great news. HBM's high cost has been a barrier to entry. If ZAM materializes, it could democratize AI access.
My honest take as a semiconductor analyst: the spec numbers are attractive, but the 'valley of death' between prototype and mass production is the real battle. Many memory technologies have died there.
For countries like Brazil, lower AI infrastructure costs would be a direct benefit. This technology has the potential to narrow the digital divide worldwide, not just in developed nations.
Honestly, catching up to SK Hynix's technical lead won't be easy. HBM's track record and yield improvement know-how can't be acquired overnight. But I respect the challenge itself.
I research semiconductors at a Swedish university, and combining with EMIB makes sense. However, there's a risk of becoming too dependent on Intel's packaging technology.