Overclocking master and Thermal Grizzly boss der8auer obtained a set of burned RTX 5090 graphics cards, power supplies and cables.Through disassembly experiments, it was revealed that the reason for the burnt power supply interface was not that the third-party wires or the user did not plug it in tightly, but that there was a serious current distribution imbalance problem in the 12V-2x6 interface.
der8auer used its own public version of RTX 5090 with CORSAIR AX1600i power supply and original cables, and ran the FurMark stress test (the graphics card power consumption is about 570W) while ensuring that it is fully plugged in.
Actual measurement data from thermal imaging cameras and current clamps showed that the temperature of some wires rose to 60°C in just 45 seconds, and the hot spot temperature of the connector soared past 150°C in 4 minutes.
According to the 12V-2x6 standard specification, the current limit of each pin is about 9.5A, but der8auer found that the current distribution of the six 12V power supply lines is extremely uneven.
One of the wires carries a current of up to 22A (approximately 264W), which is more than 2 times the standard upper limit, while the remaining wires only carry 2-3A, which means that with a total power consumption of 570W, nearly half of the power flows through a single pin.
der8auer pointed out that when the GPU power consumption approaches 600W, the small pins of the 12V-2x6 interface have extremely low fault tolerance for current distribution. As long as there is a slight difference in contact resistance among the six wires, the power will be tilted to the path with the lowest resistance, causing the wire to be instantly overloaded.
He almost completely reproduced the burning process under the condition of completely plugging it in, proving that plugging it in properly does not guarantee safety, but if it is not plugged in properly, something will happen. A large number of burn cases have been attributed to improper user operation. This conclusion may need to be re-examined.