As reported by Igor Wallossek: Igor’s laboratory, (opens in new tab) The included quad 8-pin to 16-pin adapter with GeForce RTX 4090 is hackable and can draw 600W of power from just three 8-pin PCIe power connectors. But of course, this is just an experiment done in the name of science. I wouldn’t recommend trying this with an adapter for obvious reasons. Always use the adapter that came with your GeForce graphics card and follow Nvidia’s specifications. However, if someone reverse-engineers this hack to create a product that you can sell online, you should avoid it.
Nvidia’s power adapters are more than just power splitting devices. An adapter that detects which of the four 8-pin power plugs is active. This allows the end user to make the card functional by only running 3 auxiliary power connections to the adapter, but the TDP is as low as 450W for him. With all four plugs connected, the GPU can access 600W if the power delivery system allows it.
Nvidia’s power adapter does this by relaying which power plug is being used directly to the graphics card via four small wires attached to the 12VHPWR power connector. Two of the four wires are active and tell the GPU whether it’s safe to boot the graphics card, depending on how many 8-pin power plugs are connected.
Interestingly, however, Wallossek discovered that simply plugging a secondary 2-pin plug into the 6+2-pin PCIe power connector can trick the adapter into thinking the plug is active. Make the adapter think all four plugs are active, activating the entire 600W power budget. To investigate further, Wallossek looked at the individual wires and found that the two sensors that tell his GPU which power plug was active he could do the same by shorting the wires. .
This is dangerous and can lead to full-blown system failure, and the power adapter can catch fire due to the wires overheating the plastic plug. As for the sensory wire hack, caution is even more important as this hack can create a triple 8-pin power adapter instead of a quad 8-pin adapter for the GeForce RTX 4090. Again, Wallossek explained that he conducted experiments and ended up with questionable adapters on the market. If such a device is on the market, avoid it at all costs.