It depends on what you are trying to make, but there are workarounds for most things, and it becomes more of a cost and volume issue than a showstopper. If you

It depends on what you are trying to make, but there are workarounds for most things, and it becomes more of a cost and volume issue than a showstopper. If your yield is low and you still want the volume, then run more wafers, but then you need access to more DUV machines and more wafers. If your defect density is too high, then design smaller chips with a higher chance of avoiding defects, which is what Hauwei are doing - split processor into multiple chiplets (NVidia do this too, to raise yields and reduce cost). HBM3E usually has 5-6000 vias, but doing this with multi-pattern DUV without defects is tough, so CXMT currently drop that to 3000, at a cost of some loss of thermal and voltage stability. HBM:processor production ratios aren't what Huawei would like, so they mitigate this at system level by putting an optical memory bus on the GPU chip and sharing memory across the system. Not everything is a huge LLM - smaller models like recommendation systems don't have so many parameters and need so much memory, so why waste HBM on them? ByteDance use their SeedChip acelerator for this, currently made by TSMC (using an older sanctions-approved 28mm process), which instead etches dense RRAM on die beside the processor. There is also a time dynamic to this, with China still using pre-sanctions equipment and chips as their domestic alternatives ramp up to replace them. One interesting part of this is HBM ... HBM is very demanding to make, and everyone had problems with it, with initially only SK Hynix being successful. Samsung and Micron took a year or so to catch up, and during this time Samsung had made a ton of HBM that didn't meet NVidia's specifications, so ended up, pre-sanctions, selling it to China, where it has acted as a stockpile to carry them over as CXMT's domestic capacity ramps up. China seems to be doing fine. Of course they would like sanctions lifted, moreso for HBM than anything else, but all that sanctions have really achieved is accelerating their semiconductor independence. They are still building 1T+ SOTA models, standing up 100K clusters of domestic AI accelerators, etc, etc.