Looks like it’s a server HPCE (High Power Card Edge)
Documentation has appeared on the Web describing a new “hidden” power connector for Asus video cards. It’s called GC-HPWR/HPCE and doesn’t really seem to be anything new.
Apparently, this is a version of the HPCE (High Power Card Edge) server connector, adapted for consumer solutions. The connector can transmit up to 600 W of power, that is, it can replace 12VHPWR, and at the same time this is enough for any modern video card.
To even connect the GeForce RTX 4090 without any wires.
The connector is divided into four groups of pins, sixteen of which are for power supply, and twelve for communication between the motherboard and the video card. The size of this connector is comparable to a regular PCIe x1 connector.
Asus itself has already begun to use such a solution, but for now we can only guess whether other manufacturers will use it.