Micron accelerates HBM4 shipments amid fierce market share competition in AI memory

Micron’s move to mass produce its advanced HBM4 memory chips signifies a strategic push in the high-performance AI hardware market, yet the company faces tough competition from Samsung and SK hynix as market share remains elusive.

Micron’s attempt to turn artificial-intelligence memory into a more durable growth business has already moved past the sampling stage. On March 16, 2026, the company said its 36GB 12-high HBM4 had entered high-volume shipment for Nvidia’s Vera Rubin platform. Even so, the latest market data show how much ground it still has to recover: Yonhap reported on September 3, 2026, citing Counterpoint Research, that Micron held 18% of global HBM revenue in the April-June quarter, behind SK hynix on 50% and Samsung Electronics on 33%. (stage-investors.micron.com)

The commercial logic for the push was visible well before HBM4 reached that point. Reuters reported after Micron’s June 25, 2025 results that third-quarter HBM sales had risen by nearly 50% from the previous quarter, while the group forecast fiscal fourth-quarter revenue of $10.7 billion, plus or minus $300 million, ahead of the $9.88 billion expected by analysts tracked by LSEG. Reuters also said Micron had created a cloud memory business unit in April 2025 to serve hyperscalers and HBM demand more directly, a sign that the company was reorganising around AI infrastructure rather than treating it as an add-on market. (investing.com)

What changed after that was pace. DigiTimes reported on June 13, 2025 that Micron had delivered 36GB 12-layer HBM4 samples to multiple major customers using its 1beta DRAM process, with mass production then expected in 2026. TrendForce, writing a day earlier, said Micron was the second of the three big memory makers to reach the HBM4 sample stage after SK hynix, and that the recipients reportedly included Nvidia. By June 24, 2026, Micron’s own earnings materials said HBM4 was already in high-volume shipments for its lead customer’s platform and that qualification samples had been sent to multiple end-customers. (digitimes.com)

The technical step-up helps explain why the segment has become strategically important. Micron’s current HBM4 product material says the memory uses a 2048-pin bus interface running above 11.0Gb/s and can deliver more than 2.8TB/s of bandwidth per stack. When TrendForce covered the first sample shipments in June 2025, the public claim was already more than 2.0TB/s per stack, more than 60% higher performance than the previous generation, and more than 20% better power efficiency than Micron’s HBM3E. Those are not marginal gains: AI accelerators are increasingly limited by how quickly they can pull data into the processor and by how much heat and power the surrounding memory subsystem consumes. (micron.com)

The next contest will centre on density and packaging as much as on raw bandwidth. Tom’s Hardware said the preliminary HBM4 standard supports 4-high, 8-high, 12-high and 16-high configurations and uses 24Gb or 32Gb DRAM layers, opening the way to larger packages than today’s HBM3E devices. The same report said Micron lists both HBM4 and HBM4E in 12-high and 16-high versions. Micron now says it has shipped 48GB 16-high HBM4 samples to customers, giving a 33% increase in capacity per HBM placement over its 36GB 12-high part, while its June 2026 results said HBM4E, built on its 1-gamma DRAM node, is expected to enter volume production in calendar 2027. (tomshardware.com)

Yet being early on the next node has not automatically translated into a stronger market position. Yonhap’s summary of Counterpoint data said most HBM revenue in the second quarter of 2026 still came from HBM3E, with HBM4 shipments expected to become more visible only in the second half of the year. That partly explains how Samsung was able to jump from 21% to 33% in one quarter while Micron fell from 21% to 18%. Earlier in 2025, DigiTimes said Micron was aiming for HBM market-share parity with its broader DRAM business, roughly 20% to 25%. The latest ranking suggests that target has proved harder to secure than the company hoped. (en.yna.co.kr)

Micron’s argument is that timing products to customer platform launches matters as much as headline specifications. DigiTimes reported that Raj Narasimhan, who leads the company’s cloud memory business unit, said HBM4 production schedules would be aligned closely with customers’ next-generation AI platform readiness. Reuters, meanwhile, quoted chief business officer Sumit Sadana downplaying tariff-related pull-ins in 2025 as “fairly modest” and adding: “So that’s not something we lose sleep over.” The larger question now is different. Micron has shown that it can move from HBM4 samples to volume shipments. The unresolved issue is whether that execution will be enough to lift it from a technically credible third-place supplier into a business that can take material share from Samsung and SK hynix as HBM4 and then HBM4E enter broader deployment. (investing.com)