GTX 680 or HD7950 vid card and HDX-3 - how do i do power for the cards?

[MixerGuy]

Hi all

GTX 680 and HD7950 and HDX-3 - how do i do power for the cards?

I'm on a 2012 Cheese Grater Mac, and running stock video card, HDX-2 and Blackmagic video card for HDMI for the 'picture' aka the movie when doing film work - out to an HDMI 1080p screen.

I'm hoping to update my video card to one that does my 3 computer screens PLUS an HDMI all on one card, so i then have a free slot, for a 3rd HDX card, for more horsepower. I need more horsepower.

info below from a wise + trusted video card vendor / Mac Tech who i am in discussions with back and forth......

has anyone else here run into this, and how did they fix it? I hear it is possible... i am looking for specific info.

and I quote:

..."It was my understanding that the HDX-3 cards are just over the power limits for the PCI-e slots, hence the use of the auxiliary power connection.

I don't believe that you'll run into any issues in terms of power draw, however, getting the connectors situated is the tricky part.

Your Mac Pro has two auxiliary power connectors. Currently, your Radeon HD5770 occupies one, and the HDX-3 cards occupy the other.

The [cards i am looking at maybe buying] GTX 680 and HD7950 require both of the power connections.

I have had customers in the past who have modified their HDX cable by splicing it into a splitter cable. ....."

thanks for any info.