[DigitalToday reporter Daegeon Seok] Nvidia has declared it will mass-produce its next-generation AI chip, Rubin, bringing competition in the HBM4 supply chain into full swing. SK Hynix is seen as likely to have secured the initial shipments, but the landscape could change in the mass-production phase. February will be a turning point as Samsung Electronics’ participation in the supply chain is decided.

An early production announcement for Rubin, a next-generation GPU architecture that follows Blackwell, has sped up the HBM4 supply race. Nvidia CEO Jensen Huang unveiled the next AI computing architecture, Rubin, at CES 2026 on Jan. 5 (local time) and declared it was entering full-scale mass production. Nvidia has typically announced new products at GTC, its developers conference, in March or April, but it has moved the schedule up to January, leading to the assumption that the selection of initial suppliers has already been completed.

SK Hynix is the leading candidate to supply the initial volumes. SK Hynix officially announced in September last year that it had completed development of HBM4, the first in the world, and built a mass-production system. At the time, the company said it had succeeded in developing HBM4, which would drive a new AI era, and had built the world’s first mass-production system, adding it had once again proven its AI memory technology leadership in the global market.

According to SK Hynix, the HBM4 for which it has now established a mass-production system applies 2,048 data I/O channels, double the previous generation, doubling bandwidth and raising power efficiency by more than 40 percent. The company explained it minimized risks in the production process by using its proprietary advanced MR-MUF process, which has proven stable in the market, and its 10-nanometer-class fifth-generation (1bnm) DRAM technology.

The variable is February. There is a time gap between initial production and high-volume manufacturing, when volumes are supplied to the market in earnest, and the turning point is February. Because initial volumes alone cannot meet demand from global big tech, February is when yields on production lines are raised to increase volumes. Samsung Electronics’ entry into the supply chain is expected to be decided at that point.

For Samsung Electronics, February is effectively a deadline to join the HBM4 high-volume production line. Micron has already said on a recent earnings call that it had completed pricing and volume contracts for all HBM in 2026, including HBM4, and that HBM4 was expected to enter full-scale mass production in the second quarter of 2026. Micron forecast HBM4 would show faster yield improvement than HBM3E and presented a 2028 HBM TAM estimate of 100 billion dollars. That exceeds the size of the entire DRAM market in 2024.

Samsung Electronics has enough chance to turn things around. A bottleneck at TSMC’s packaging lines is a variable. If Samsung Electronics proposes a one-stop supply that links memory (HBM4) and packaging, it could play a relief role by filling shortages that cannot be met with SK Hynix volumes alone.

Inside SK Hynix and Samsung as HBM4 high-volume production nears

SK Hynix is also aware of uncertainty in the high-volume production phase. In an explanation titled “Regarding investment in semiconductor plant construction” released through its newsroom on Dec. 24 last year, SK Hynix said the most important factors in semiconductor plant construction are not only the size of funding but also how quickly funding can be secured to make investment decisions. It added that, as in Japan’s case, when the government and the private sector can raise funds quickly through various methods, the period up to construction and operation can be greatly shortened.

On the surface, it emphasized the need to improve investment regulations, but it also reflects concern that the pace of expanding production capacity in the HBM4 high-volume phase could lag competitors. With investment costs for a 10,000-pyeong cleanroom rising from about 7.5 trillion won in 2019 to about 20 trillion won in 2025 for Cheongju’s M15X, the speed of raising funds directly translates into market share.

Unlike before, the exponential increase in demand in the global AI infrastructure market means the HBM race no longer ends with securing initial volumes. That indicates SK Hynix’s dominance in the HBM market could be shaken at the high-volume production stage. Ultimately, the share of entry into the Rubin platform is expected to determine future market leadership.

The key will be how quickly the high-volume production system can be stabilized after the second quarter, when HBM4 demand picks up in earnest. February will be a turning point for whether SK Hynix continues to dominate this year and whether Samsung Electronics secures a chance to turn the tables. An industry official said, “HBM4 has become a game where production speed is as important as technological capability.” The official added, “After February, who first establishes a stable high-volume production system will affect full-year results.”