(Photo: /u/NoDuelsPolicy on Reddit)This week we’ve seen more reports of fried RTX 4090 adapters, with the count now up to a half dozen or so. Previously we just knew that some adapters were melting, and in doing so also damaging the connector on the card. It wasn’t clear exactly what was to blame for this situation. Was it the adapter, the bending of it, or some other engineering mishap? Now the intrepid tinkerers at Igor’s Lab have revealed what they believe is the culprit: the Nvidia-designed 4-into-1 adapter. This takes four 8-pin cables and routes them into a single 16-pin plug. Its poor construction is likely the cause of the issue, and photos reveal it to be a hot mess, pardon the pun.
Previously all we knew was that adapters were melting. It was theorized it was somehow related to bending the adapter, which is required due to the size of the GPUs. Their width places the connector close to most cases’ side panel, necessitating an almost 90-degree bend to move the cable out of the way. This isn’t rocket science; you don’t want to put a serious bend on any electrical connection. This might not be an issue if the connection was as solid as a rock. However, it turns out it’s not very solid at all. This is seemingly due to insufficient soldering around the wires, which is meant to keep them in place. Igor’s Lab took one of the adapters apart to investigate, and the results aren’t pretty.
According to his investigation, there are six contact patches and four wires on each side of the adapter. Two on the edges are soldered to one point each, and the four in the middle are connected to two wires each. You can see in the photo there’s a surprisingly small amount of solder used for these connections. Igor says the connections use a 0.2mm copper base with 2mm of solder per wire. That leaves 4mm of solder for the twin cable connections.
For 14 gauge wire, that’s not much. Now just imagine bending those wires at a right-angle while they are hot, and you can see the problem. This could cause the solo cables at the edge to get loose first. Unsurprisingly, that’s exactly what we’ve seen in several of the reports so far (see below). When that happens all the current will flow through the remaining wires, so they will heat up drastically.
To summarize the findings, the problem is not with the actual cables coming from the PSU. Nor is it with the connector on the PCB. It seems to lie exclusively with the adapter designed by Nvidia. This is included with every Ada GPU and was made by a third party for Nvidia. Igor assumes Nvidia wasn’t aware of how poorly they were made, or it didn’t examine them too closely. If it had, it would never have allowed its add-in board (AIB) partners to include them with its flagship GPUs.
For now, Nvidia is still investigating according. In an update, Igor’s Lab says Nvidia has reached out to its board partners and asked to have all damaged GPUs sent to HQ for analysis. The next logical step would be for Nvidia to announce a recall for the adapters. It should have new adapters made, and replace them for free. That could take some time, obviously, and will seriously piss off current RTX 4090 owners. However, those gamers will likely prefer a safer adapter in the long run. They could alternatively purchase an ATX 3.0/PCIe Gen 5 power supply, but those are still hard to find. Plus, they will be expensive. Some companies like Seasonic and CableMod are also offering 90-degree adapters as well, but they’re not for sale yet.
Until we hear from Nvidia officially, our advice is pretty simple: be careful with your adapter, and don’t bend it. If it’s currently bending due to your case’s side panel, take off the side panel.