PSU Help!

N1TR1X · 12 Jun 2017 at 11:48

Hi folks,

I have a Corsair CX750M PSU and I currently power a GTX 970 from the 6+2 PCIE socket on the PSU. The GTX 970 takes an 8 pin and 6 pin power input.

http://www.corsair.com/en-gb/cx-series-cx750m-750-watt-80-plus-bronze-certified-modular-atx-psu-na

I am looking to add a second card. Am I able to power this off the 4+4 CPU slot seen in the image below? The pinouts on the PSU for the PCIE and CPU sockets looks exactly the same.

http://www.corsair.com/~/media/corsair/product-images/psu/cxm-2015/large/cx750-850m_01.png

** Do Not Hotlink images please **

Thanks in advance!

Edit: My bad on hotlinking

Borealis · 12 Jun 2017 at 12:08

Although they might look the same, they're not! The plug might look the same but the actual wires may carry a different voltage/current. To power a graphics card, you need a PCI-E power connector - either a 6 pin or a 6+2 pin. The CX750 comes with 4 PCI-E connectors, so you should have them spare.

EDIT: Here's a review page, showing the cabling: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=416

N1TR1X · 12 Jun 2017 at 12:12

Borealis said:
Although they might look the same, they're not! The plug might look the same but the actual wires may carry a different voltage/current. To power a graphics card, you need a PCI-E power connector - either a 6 pin or a 6+2 pin. The CX750 comes with 4 PCI-E connectors, so you should have them spare.

Thanks Borealis. I unfortunately don't have any spare cables after moving house recently

The GTX 970 has a 6+2 in and a 6 in as supplementary power. This is powered off the single 6+2 output on the PSU so I am a little confused how I can power a secondary card.

Do I then have to get a 6 to 6+2 cable and a 6 to 6 cable to power a second card, thus using 2x6pin PCIE outputs on the PSU?

Borealis · 12 Jun 2017 at 12:34

That kinda sucks losing the cables in a house move. You really need the corsair cable as the PSU end of it will be specific to the unit. If you have any spare molex connectors (as in they're missing as well), you can get molex to PCI-E cables/adapters.

If that isn't an option either, then you're possibly looking at needing a new PSU just to power the 2nd 970.

To be honest, I wouldn't bother with SLI. In the last couple of weeks, I've upgraded the system in my signature from 980Ti SLI to a single 1080Ti. SLI 980Tis give about the same performance as a single 1080, but you're dependent on SLI support for any games you play. Most modern/recent games are somewhat lacking in SLI/Crossfire support.

What do you play and at what resolution? You may be better off saving up for a better single card to replace the 970.