If you're buying a used RTX 4090, be careful who you buy it from. And where to buy it.

According to reports on Chinese forums such as Chiphell and HKEPC (Via Guru3D), people have bought Nvidia's best gaming cards with big bucks, only to receive cards with no GPU or memory.

Scammers do scam, and there is good reason to believe that this particular scam is related to the ban on RTX 4090 sales in China. It is not a stretch to believe that the AD102 GPUs on the cards in question have been removed and repurposed to satisfy some of the insatiable (and therefore lucrative) demand for GPUs for AI and server applications.

The cheapest RTX 4090 we could find on Newegg is the MSI Gaming X Trio for $2,099. This makes the official MSRP of $1,599 look like a bargain. And this is all due to demand for AI GPUs and the Chinese ban. Simply put, Nvidia can make more money on the L40 and RTX 6000 series cards than on the RTX 4090. Limited supply will drive prices up.

But demand is also surging. The ban was born out of the U.S. government's desire to stay ahead of China in the AI arms race. It is in the interest of national security. So it is trying to limit China's access to the tools it needs. Whether banning the chips and products themselves or the semiconductor manufacturing tools China needs to make them, the demand for AI hardware in China far exceeds the available supply. This is a one-two punch. The combination of surging demand and diminishing supply means higher prices.

The time seems ripe for the scumbag scammers. Ostensibly, "Why not just take the GPU out of a $1,599 graphics card, pop it into an L40-style PCB with a blower fan, and make a ton of money?" Easier said than done; a few cards may not be worth it, but 100,000 cards...

Of course, this is just speculation on my part, but I find it hard to believe that a small-time scammer would go to the trouble of removing a dead GPU when they could just send an intact dead card. This suggests something much bigger.

And that is why these reports worry me. I expect more victims of this particular scam to come forward. With this kind of activity occurring, one should be very careful where they purchase their RTX 4090. If you find a deal that looks too good to be true on the used market, simply put, it probably is.