Creating a 48GB Nvidia RTX 4090 GPU – Brother Zhang's Repair Shop (Ft. 张哥) [video](www.youtube.com)
50 pointsby adityaathalye10 hours ago1 comment
  • stefan_6 hours ago
    Given GNs other coverage its a bit odd for them not to mention why someone would bother to make a 48 GB 4090. Or the whole side business of these "repair shops" of removing cores for sanction busting AI cards, reassembling the now worthless PCB with the cooler and scamming some unsuspecting customer that thinks they are getting a deal.
    • jdboyd5 hours ago
      If the cards were legally acquired in the first place, I don't see how they (the shop) have any moral reason not to upgrade the cards however their customers want. It isn't their laws that prevent high memory cards. And the appeal of this is not just limited to sanctions limited countries. The prices for these modified cards are wildly cheaper than any vaguely equivalent card that and video will allow to be sold from an authorized OEM.

      Five for one would love to be able to do that sort of upgrade work and offer it in the Continental US.

      It is true that they did not entirely specified what happened to the waste boards here. Clearly somebody who is stripping parts is then reassembling cards and selling them on eBay or other places. I hope it is not this shop, but clearly they didn't even try to disclaim that behavior. I'm not saying they didn't disclaim it because they're guilty, it could just have not come up.

      • nerdsniper5 hours ago
        Generally there are a number of valuable components on the waste boards which can be parted out, and often kept on-hand for other repairs. Each of the chips on those boards are valuable for future repairs, and (in the USA at least) often quite difficult for repair shops to obtain. Here[0] is an example of such a chip from a MacBook Pro - it's a proprietary, custom Apple component so generally you can only obtain them through salvage.

        I don't know if this shop sells any of their scrap into the scam industry, but I bet they'd have a white-hat market available for a lot of it.

        0: https://store.rossmanngroup.com/zc8-u9850-edp-mux-a1707-a199...

    • nerdsniper5 hours ago
      > removing cores for sanction busting AI cards, reassembling the now worthless PCB with the cooler and scamming some unsuspecting customer that thinks they are getting a deal

      I'm either particularly ignorant or this claim has some inconsistencies. My understanding is that you cannot "remove cores" from a GPU. The titular RTX 4090 (Ada Lovelace) comes with 16,384 CUDA Cores. At face value, it sounds like you're saying that Brother Zhang's repair shop uses some nano-technology tools to open up the Ada silicon itself and then somehow disable or destroy or dissect the silicon to reduce the core count. And then they sell these reduced core counts GPUs (???).

      That's obviously preposterous, but I'm having trouble steelmanning this to re-construct your actual meaning.

      • 1111111011015 hours ago
        remove cores = remove the GPU die
        • nerdsniper5 hours ago
          Okay so 'stefan_ is arguing that the board which now has no GPU at all and is completely non-functional then gets sold to unsuspecting consumers? In that case, why would the scammer sell the 4090 board at all? At that level of fraud, the scammer could just as well send a circuit board from an alarm clock, or a brick. How does this behavior reflect back on Brother Zhang's shop at all?

          So far, everyone's concepts have felt pretty half-baked. Perhaps someone could point me to some actual reports relating to this topic which go into real detail about allegations around how these repair shops contribute to fraud. I'm not having a lot of luck engaging here, but maybe I'm just a bit dim-witted.

          • 1111111011014 hours ago
            https://www.youtube.com/watch?v=zJlFmyr8c14 https://www.reddit.com/r/hardware/comments/192z13d/scammers_...

            > In that case, why would the scammer sell the 4090 board at all? At that level of fraud, the scammer could just as well send a circuit board from an alarm clock, or a brick.

            Plausible deniability. With a real-looking GPU, the seller can always fall back on user error, bad PSU, driver issue, PCIe slot problem etc.

            The buyer may even doubt themselves at first and spend time reseating the card, reinstalling drivers, swapping cables, or testing another system. By the time they're confident it's not their fault, the return window or dispute period may already be gone.

            None of that works if you send a brick or an alarm clock PCB - the fraud is immediately obvious.

            • hakfoo2 hours ago
              For that kind of scam, all you really need the cooler, which are often parted out for legit reasons (watercooling, replacements, probably some specialized high-density and rackmount plays) and may be available as a spare or "second-shift" offering.

              It would probably be easy to produce a PCB that's the right size to fit a 4090 cooler, but just contains 90 cents worth of random SMD parts. And you can produce them in quantity when you want them rather than relying on an erratic supply of stripped "real" PCBs.

            • nerdsniper4 hours ago
              Great resources, thank you. Makes sense.
    • didntknowyou6 hours ago
      did you bother to see the video? they are a legit repair shop being transparent about everything, no one is in the dark they are getting a new product