CXMT’s entire portfolio is made without EUV, and CXMT claims to have acceptable yield and performance comparable to other producers.

Keep in mind that the high bandwidths of modern RAM modules aren’t really a property of the RAM cells so much as a property of the read and write circuitry and the DDR or HBM transceivers, and those are a large part of the IP but a small part of the die. There is no such thing as “double data rate” or “high bandwidth” DRAM cells. Even DRAM cells from the 1990s could be read in microseconds. Reading and streaming your fancy AI model weights is an embarrassingly parallel problem and even 1 TB/sec does not even come close to stressing the ability of the raw cells to be read. This in contrast to, say, modern tensor processors where the actual ALUs set a hard cap on throughput and everyone works hard to come closer to the cap.

Take a look at what makes a modern computer with good RAM performance work: it’s the interconnect between the RAM and processor.