8pin PCIe gpu - 6 pin psu

[Fondue]

this 1070 has 2 x 8pin power plugs on it and the eGPU I have has a 6 & a 6+2 power plug.. the gpu does not seem to be functioning correctly if I just plug in the 6+6 or the 6+(6+2) and I've read people fixed the issue buying 6pin to 8 pin adapters for the psu plug

does the card have to have 8pins connected?

[Melena]

Typically yes. If it has 8 pin connectors, it is needing the 8 pins to get the full power draw from the PSU. Using 6 pins in an 8 pin gpu may sometimes work, but can create severe stability issues, especially if overclocked. Either use adapters to make the 6 pins 8 pins, or new PSU

[Fondue]

I bought 2 6 to 8 pin adapters, and the eGPU magically works now! huzzah

[Niya]

Just bear in mind that you might overburden your PSU with that. A 6-pin is meant to deliver 75W, and 8-pin 150W. So by using the 6-to-8 adapters you basically make the GPU draw (up to) 150W over a cable/rail that is only meant to deliver 75.
It can work since GPUs most of the time don't max out their power connectors, but spikes can easily reach the limit.