MediumV Technology Geopolitics & AI12 October 2026, Monday
China's CXMT memory breakthrough knocks Samsung and SK hynix lower
Chinese memory maker CXMT said in Shanghai at the weekend that it had made progress on a 4F² cell structure, replacing the mainstream 6F², and would release server memory based on it by the end of 2026. On 12 October Samsung fell 3.6% and SK hynix 3.4%.
Investing.com reported on 12 October that CXMT chairman Cao Kanyu announced a key advance in moving to a 4F² cell using the company's proprietary vertical surrounding gate (VSG) transistor. In a 4F² design each memory cell occupies four times the square of the smallest line width; commercial DRAM today uses 6F². According to Yahoo Finance, the shift means moving the transistor channel from horizontal to vertical, a major change in manufacturing. The company plans to release next-generation DDR5 RDIMM modules for servers by year-end, but gave no detailed specifications or firm date.
Markets reacted on 12 October. Samsung Electronics fell 3.6% to 252,500 won and SK hynix 3.4% to 1,624,000 won, while CXMT's own shares slipped 3.1%. Rivals' roadmaps run later: SK hynix unveiled its 4F² plan in 2025, and Samsung is reportedly targeting 2028 for volume production of sub-10-nanometre DRAM on this design. Yahoo Finance says CXMT's fifth-generation G5 platform entered volume production in September, and its July listing in Shanghai raised 8.6 billion dollars, mainland China's largest semiconductor IPO. A product launch and high-volume manufacturing are separate thresholds, and yield data could not be verified.
Talay assessment
Bottom line
By announcing a product timeline for the new cell architecture ahead of its rivals' 2028 target, despite export controls, CXMT shows that China's substitution drive is gathering pace in memory too. But a launch is not volume production, and there are no yield data. The most likely path is that markets partly restore the Korean memory premium while waiting for the first customer validation of CXMT's year-end product.
Likely effects
- Korean memory makersNegativeWeeks
China's 4F² timeline calls into question the technology-lead premium of Samsung and SK hynix; the drop of more than 3% on 12 October is the first pricing of that perception.
- US export controlsUncertain1–6 months
Architectural progress reinforces the impression that equipment restrictions can be worked around, adding pressure in Washington to tighten controls on memory production tools.
- TürkiyePositive6 months+
Türkiye imports its memory; a second Chinese supplier gaining scale in server memory could, over time, create price competition for Turkish companies building data centres.
Possibilities, ranked
- 1Product arrives, volume lags55%
CXMT ships 4F²-based DDR5 RDIMM samples by year-end, but high-volume production slips into next year; the Korean premium partly recovers.
Watch: A CXMT announcement of customer samples or certification for the 4F² product
- 2Timeline holds25%
The product arrives on time with competitive yields, and pressure builds on Korean makers' share of server memory.
Watch: Orders for CXMT server memory from Chinese cloud companies
- 3Controls tighten20%
Washington imposes new export restrictions on tools used for vertical transistor production, and CXMT's timeline breaks down.
Watch: A new BIS rule on memory equipment or an Entity List decision
Probabilities are calibrated judgement based on the sources, not measurement, and are revised as new information arrives. Not investment advice.
Market reaction
Indicators affected
- Samsung Electronics▼ −3.6%
- SK hynix▼ −3.4%