CXMT validates the DRAM design Micron abandoned, with server samples due December 31
CXMT says engineering validation of its sixth-generation 4F² DRAM platform is complete and first server-memory samples reach clients by December 31, a dated test of the shortage behind Micron's 86.8% gross margin.
Vincent Jiang · 3 min read
Validation done, samples dated
CXMT−2.50% — CXMT, down 2.50 percent today, China's largest DRAM maker, used its first earnings report since its July Shanghai listing to say engineering-sample validation of its sixth-generation DRAM platform is complete: core performance targets met on real wafers, with mass production to follow customer qualification 1.
It was the first public confirmation the platform rests on 4F², a cell layout giving each memory cell four times the square of the smallest line a fab can print, roughly a third less area than the 6F² cells the industry ships today 13.
First DDR5 RDIMM modules, registered memory for servers, go to customer testing by December 31, servers first, then other lines; Samsung plans sub-10-nanometre 4F² mass production only in 2028, and SK hynix−7.62% — SK hynix, down 7.62 percent today published its roadmap in 2025 12. The year-end pledge is not new: The Inference covered it on October 11 12. The validation, Micron's−4.83% — Micron, down 4.83 percent today exit and the quarter's numbers are.
Micron says the physics does not work
Micron President and CTO Scott DeBoer told a October 21 webinar that DRAM density is set by the spacing capacitors require rather than the nominal cell footprint, so 4F² buys little density at sharply higher cost; after more than two decades of research, Micron scrapped commercialization and will keep scaling 6F² toward stacked 3D DRAM 4.
CXMT's answer, at its October 30 briefing: "the layout and structure of word lines and bit lines must be considered as well, not just the capacitor" 3. Samsung and SK hynix are still building 4F² 4. The argument is over margins the shortage created: Micron closed its fiscal fourth quarter on September 3 with an 86.8% gross margin on $54.2 billion of revenue, up from 44.7% a year earlier, and CXMT printed 89.5% 56.
The shortage took Micron's gross margin from 44.7% to 86.8% in five quarters
Data
| Gross margin | |
|---|---|
| Q4 '23 | -0.7% |
| Q1 '24 | 18.5% |
| Q2 '24 | 26.9% |
| Q3 '24 | 35.3% |
| Q4 '24 | 38.4% |
| Q1 '25 | 36.8% |
| Q2 '25 | 37.7% |
| Q3 '25 | 44.7% |
| Q4 '25 | 56% |
| Q1 '26 | 74.4% |
| Q2 '26 | 84.6% |
| Q3 '26 | 86.8% |
The slowdown number, and the checkpoint
CXMT's quarter was 118.7 billion yuan of revenue (about $18 billion), up 613% year on year, with 54.4 billion yuan of net profit 235. Sequential growth slowed to 19.3% from more than 90% in the second quarter, the first number to ask whether pricing is cresting; Morningstar's Jing Zhiwei expects stability rather than explosive growth 23.
CXMT ended September with about 285 billion yuan ($43 billion) of cash and holds 9.5% of global DRAM revenue, up from 7.6% in the first quarter, against Samsung's 39.4%, SK hynix's 24.9% and Micron's 23.3% 578. If the samples qualify, server buyers gain a fourth supplier, and the incumbents' margins are what pays for it.
CXMT's 9.5% of global DRAM revenue still trails the three incumbents
Data
| Value | |
|---|---|
| Samsung | 39.4% |
| SK hynix | 24.9% |
| Micron | 23.3% |
| CXMT | 9.5% |
The other side has dates too
Micron CEO Sanjay Mehrotra expects memory to be much tighter in 2027 and 2028 than in 2026, with 75% of 2027 output already allocated, and TrendForce, in an assessment relayed by an industry roundup, sees no full-scale 4F² commercialization before 2028 and no spot-price effect yet 89.
CXMT itself says the product "cannot be entirely converted into immediate short-term profits," with mass production paced by customer validation 2. Micron fell 5.3% on October 30, the day CXMT reported, and trades near 12 times its $74.33 of fiscal 2026 earnings per share, about a quarter below its June record 57.
The market has already priced the boom's end; December 31 is the first date anyone can check it.
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