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Both nVidia and AMD have made comments suggesting they are doing 7nm but there's also been suggestions about the difficulty in doing that and that they may even be targeting 10nm instead of 7nm.
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7nm is an order of magnitude harder than anything that came before. If you're not seeing nVidia or AMD producing or even announcing parts at this node, then you're not going to see real parts coming from a random bitcoin company any time soon. nVidia and AMD have $billions to invest. 7nm parts will come, but not soon. 7nm bitcoin mining chips will only be used to backfill fab capacity if they don't have other production to run.
Every new technology node is massively more difficult than the preceding one. Transition to 7nm changes all sorts of things. It's going to take literally $billions to get this tech up and running. No one's going to waste wafers on bitcoin chips, unless for fab testing because it's actually a very simple design. Maybe this is what they're hoping for? I just don't see it happening.