First of all, because it is a modular cable. For a PSU modular port, not all 8pin are used and it is by design of the PSU manufacturer.

Secondly, the 12VHPWR connector is a 12pin connector. You will never see 24 wires (3x8pin) or 32 wires (4x8pin) all jamming into a small 12VHPWR connector.

In fact, if you check and remove the sleeving from the original Nvidia adapter, you will see there are 2 wires from each 8pin only, not 8 wires from each 8pin connector.

Now, let's take a look at the PSU vendor 12VHPWR cables, you can see there are blank pins too and only 2 sense wires are used.

For 12VHPWR, you should expect to see 14 dedicated wires in total (6 x 12V + 6 x GND + 2 x SENSE)

Was this article helpful?
Thank you!