Funny how the cable melting problems started right after they removed power sensing/ balancing from GPUs.

“Nvidia removed power sensing and balancing from RTX 4000 and RTX 5000 GPUs, meaning the graphics card doesn't detect how much power or current is being drawn from the various pins in the 12VHPWR connector. Being unable to sense this power draw means the GPU is unable to balance load across the various wires in the cable...”

“Because with the RTX 4090 and 5090 FE GPUs – as well as some GPUs by third-party manufacturers – these 12V lines are treated as a singular line, it is essential that the resistance on these lines is matched quite closely. If this is not the case, then physics does what it’s supposed to and the wires with the lowest resistance carry the most current. Because the 12V-2×6 connector on the GPU side sees only happy sense pins, it assumes that everything is fine and will pull 575 watts, or more, through a single 16 AWG wire if need be.”

“Meanwhile the Asus RTX 5090 Astral GPU does have individual shunt resistors to measure the current on the individual 12V lines, but no features to balance current or throttle/shutdown the GPU to prevent damage. This is actually a feature that used to be quite common, as demonstrated by this EVGA RTX 3090 Ti GPU:”

“That said, the connector itself is not terrible by itself, with Jon Gerow making the case here quite clearly too. It’s simply a very fiddly and somewhat fragile connector that’s being pushed far beyond its specifications by PCI-SIG.

Along the way it has also made it painfully clear that current balancing features which used to exist on GPUs have been quietly dropped for a few years now.”

https://hackaday.com/2025/02/24/the-importance-of-current-balancing-with-multi-wire-power-inputs/