MP 1,1-5,1 Draw power from SATA for GPU?

[sanfrancisofont1984]

Lots of graphics card use 8 pin + 6 pin power connectors. I got a dual 6 pin to 8 pin cable. And I am about to get a dual SATA power to 6 pin cable. I wonder could I just use SATA power from 2 out of the 4 easily accessible drive bays or I have to open up the top third of the Mac Pro case?

My current setup is Nitro+ RX 580 with its 6 pin power simply unconnected on 5,1. I have not experienced shutdown/crash yet but the heaviest thing I did was probably just Unigine Heaven/Valley.

I am aware of Pixlas mod, prefer not to do it right now.

 

[MIKX]

I normally use an MSI Armor RX 580 8gb in my cMP which doesn't need the DUAL SATA to ONE 6 pin.

Occasionally I use a Sapphire Dual-X HD 7970 3gb EFI flashed & down-volted with this setup ( for running X-Plane 11.
The Dual SATA to ONE 6 pin cable is probably unnecessary but better safe than sorry and the EVGa PowerLink is just good at what it does.)

EVGA PowerLink with AMD GPUs

Just got the EVGA PowerLink working with my Sapphire Dual-X 7970 3gb. IMPORTANT : The power input sockets on the PowerLink are 2 X 8 Pin female and cannot be changed. The EVGA PowerLink ensures that exact power demanded by a GPU is supplied. That said, one must still supply enough power to...

forums.macrumors.com

Works very well; strong, cool and quiet.

I've seen online articles that say that the Nitro doesn't need the 6 pin powered but I WOULD have it powered for my uses if I had one.