No ban is perfect, there is always some loopholes or illegal exports this is to be expected, but if it prevents large scale transaction then it it is achieved its goal.
The question is rather do they we need a lot of gpus to train or training with older gen gpus is not competitive is a different problem.
It doesn't prevent the transactions, it only makes them more expensive than they would have been otherwise. If the the US was able to covertly buy enough titanium from the USSR for the SR-71 program, China can buy the latest GPUs if it believes AI competence is in its national interests.
Oh look, there's sudden demand for H100s of by dozens of small companies in Brazil, Hong Kong, Vietnam, Indonesia, Singapore, Malaysia and Thailand. I better not look too closely at them or I won't get my sales bonus for this quarter.
Harder and more expensive, but far from impossible. I doubt they pay more than doubles Nvidia's sticker price, all told. My comment was inspired by recent real-life events; Nvidia got into legal trouble in the last couple of months for turning a blind eye to questionable transactions - if you're curious about the mechanics of GPU sanctions-busting, read up on the governments accusations against Nvidia, and this was for low-hanging fruit.
The article has one analyst speculating they used tens of thousands of H100s (50,000 IIRC) instead of the 10,000 A100s the Deepseek CEO owns up to. They can afford to pay exorbitant markups for the logistical nightmare of importation through 3rd party countries at scale.
edit: AFAIK, the sanctions don't prevent Chinese AI labs from renting GPUs from any cloud provider. To simplify logistics, a shell company could avoid shipping the cards to the mainland by simply settings up a data center in not-China and give the parent company full access. I suppose the US government has to balance sanctions against Nvidia's share price, so they can't be too aggressive, there are just too many loopholes for demanded shock not to have been a consideration.
When I was working in Beijing, we definitely had resources we couldn’t access locally but could easily access remotely so it didn’t really matter.
https://www.tomshardware.com/tech-industry/artificial-intell...
If you follow the news, several people (bankers) will trade with Iran despite the repercussions (jail) of doing so. There is a premium but at the right price someone will execute.
This boils down to the same thing in a market economy. If the price is too high, that prevents the transaction.