China's CXMT to Start HBM3E Memory Output at 20-30% Yields

ChangXin Memory Technologies, China's largest DRAM maker, plans to begin limited production of HBM3E, the stacked memory used alongside AI processors, within the next two months, even though only 20% to 30% of the chips meet specification. SK Hynix, the market leader, runs about 70%. Reuters reported the yields and timeline citing two people familiar with the matter.

The pressure to ship is concrete. Chinese AI chipmakers have "struggled to obtain enough advanced memory to increase output," the sources told Reuters, and buyers routed to unofficial channels since Washington tightened HBM export controls in December 2024 are paying "several times more" for the chips. Low yields make production expensive because a large share of wafers must be discarded or reworked.

In testing, one source said "CXMT's HBM3E performance was closer to SK Hynix's previous-generation HBM3 than to the South Korean company's HBM3E." CXMT has sent domestic AI chip designers two versions, a standard design and an updated one intended to lift yields, and the chips are expected to cost more than comparable overseas products. The Information first reported CXMT's HBM3E plans; Reuters is reporting the yield and timeline details for the first time.

The ceiling above CXMT is still high. Counterpoint Research puts SK Hynix at 50% of global HBM revenue in the second quarter, Samsung at 33% and Micron at 18%, with most of it coming from HBM3E. Samsung said in July it had expanded HBM4 sales and shipped HBM4E samples to major customers, leaving CXMT "at least one generation behind in commercial HBM production." Reuters also noted last month that Huawei, Cambricon, MetaX and Iluvatar CoreX had already raised prices for current and next-generation AI chips by 20% to 50% as memory costs squeezed their ramps. CXMT did not respond to a request for comment, and SK Hynix did not immediately respond on the yield estimate.