combination of both, they published papers so we can clearly see they are not just duplicating old methods but coming up with new optimizations. ... yet we can't rule out that they used Nvidia. I don't even see how the export restrictions work, it's stupid. A Chinese company can go to another country, say France or Canada, setup a business buy a bunch of GPUs then make it available to their subsidiary in China. The export restrictions doesn't restrict usage/sharing/renting as far as I know...