I'm way out of my knowledge and comfort zones here. Not come across
PCI-e until this morning.

Son has a gaming PC, and has a Geforce GTX 1080 graphics card to
install, to replace a Geforce GTX 670 card.

The 670 has two 6 pin sockets and the leads from the power supply have
two 6 pin plugs (but see below).

The new 1080 has two 8 pin sockets but came with two converter cables,
each of which has two 6 pin sockets and one 8 pin plug.

However, the original power supply leads, which were connected to the
670, also each have an additional 2 pin plug.

I have read the Wiki page on the subject, but am not much wiser. By
carefully studying the profiles of the various plugs and sockets, we
have connected one 6 pin and one 2 pin power supply lead to each of the
two 1080 8 pin sockets, and that seems to work in that the PC is running
and the new card configuration screen is there.

I suppose I really just want someone to say Yes! that is how it should
be done :-) We have not used the little converter (?) leads that came
with the card.

--
Graeme

Graeme wrote:

I suppose I really just want someone to say Yes!

Yes you're fine, the 6+2 cables from your power supply can be connected
to either 6pin, or 8pin sockets on cards

Graeme wrote:

8 pin sockets

Does anyone understand the logic of an eight pin PCIe connector carrying
five ground wires and three +12V wires, rather than four of each as the
eight pin EPS12 connector does?

In message , Andy Burns
writes
Graeme wrote:

I suppose I really just want someone to say Yes!

Yes you're fine, the 6+2 cables from your power supply can be connected
to either 6pin, or 8pin sockets on cards

Thanks Andy. It certainly all seems to be running, and he says at
optimum speed or whatever, so we seem to have muddled through.
--
Graeme

On 09/04/2017 09:49, Andy Burns wrote:
Graeme wrote:

8 pin sockets

Does anyone understand the logic of an eight pin PCIe connector carrying
five ground wires and three +12V wires, rather than four of each as the
eight pin EPS12 connector does?


2 of the "ground" wires are "sense" wires that the card can use to
determine whether the 6 or 8 pin plugs have been attached to the card.

At least that's the official definition...