Hardware

You can buy them from unofficial sources if you're lucky enough to find one. The OP in that thread was offered one from and unofficial, small batch of AI cards and had to pay about 1.5 times what you'd pay for a regular 4090. The cards may very well be from a similar source to this one.

So "you can buy 2-slot 4090s" is technically correct, but isn't actually true for most people even if they had the money.