GTX 980 ti PSU Question

[KoD Krysco 51]

I see that the GTX 980ti GAMING6 from MSI has 2 8 pin power connectors. I have an EVGA supernova 850 PSU and for the VGA cords, the provided cable is a y-connector with a 6+2 on one end and a 6 on the other. That alone wont work.

Could I just use two vga cables and only use the 8 pin portion of the Y connector on each one? I dont really know of any other way. The PSU has 4 VGA spots on the back and I have atleast 2 cables that I mentioned above.

I wasnt sure if it was safe to power a single GPU by two different ports on the PSU?

 

[Rhezner]

Yes it would work. The Psu only gives as much power as is needed

 

[atheus]

This is a bit strange... the reason it has 2 8 pin connectors on the video card is because it requires 2 separate cables from the PSU. The reason is that those cables are rated for a certain amount of wattage - 8 pin connectors (and the wires behind them) are rated for 150 watts each, so the ideal situation is that you just run 2 8 pin cables from your PSU to the graphics card to proivde the needed 2x150 watts.

The Y adapter that you have is for people whose PSU for whatever reason might not have a second 8 pin cables available, in which case they could use 2 6 pin cables (rated at 75 watts each) to make a single 8 pin (150).

Long story short, yes, you need to run 2x8 pin PCIE cables (or 4x6 pin PCIE cables merged into 8 pin connectors) from your PSU to your graphics card to deliver the specified 375 watts. Running any fewer than that would mean pulling more current over a cable than it was intended to deliver.

For reference...
PCIE slot: 75 watts
6 pin PCIE cable: 75 watts
8 pin PCIE cable: 150 watts

This is why you can split an 8 pin into 2 6 pin cables, or merge 2 6 pin cables into an 8 pin.