Second power supply for gpu?

[Coaxialgamer]

Hello,

So i am installing a second gpu in my build, and i was wondering if i could use a second power supply for to power the extra card instead of replacing my original power supply by using the 6/8 pin pcie connectors.

[TheRandomness]

Depends. What's your current PSU?

[Guest Kloaked]

Yes, but you should just replace the PSU with a sufficient one. You're better off.

[Oshino Shinobu]

You can, but you will need a connector to turn on both PSUs when you press the power button. 

 

Replacing the PSU is most likely the better option, what is your current one?

[Coaxialgamer]

I have a cx 750m and pan on using a cx 500 for my second r9 290x

[Chumgus24]

If your case is modded, and you have the wall sockets, then yes.

[infamous_last]

You can, but you will need a connector to turn on both PSUs when you press the power button. 

 

Replacing the PSU is most likely the better option, what is your current one?

You can get a loom to do this function, like this one

 

[Coaxialgamer]

I was thinking of using the 8 pin connectors on the psu to power the gpu.

I heard the cx series have a bad reputation, is the gs 800 a good psu, i can get it for cheap.

[Khajiit Dealer]

The CX has quite a bad reputation on this forum, yes. I have a refurbished one that hasn't failed, but I digress. 

 

I'd go with this PSU even though it's 50W over the watts you want:

 

https://www.google.com/shopping/product/7306833332729589450?sclient=psy-ab&biw=1804&bih=889&q=evga+800w&oq=evga+800w&pbx=1&bav=on.2,or.r_cp.&bvm=bv.103627116,d.cWw&tch=1&ech=1ψ=oKkLVr3ABovq-AHUy6G4Aw.1443604894930.7&prds=paur:ClkAsKraX9cIslZqE3Z8UaumMzp0Vh6ShEgeXGTzyDPcsDpe_HCYhW3GQndEG6e3D0IJvslkuKMLLvYMKN1IK1kOn2LWBauNBiuCzxeEj3A10vywEHGiXWU_ERIZAFPVH70mm90fa2pNYTHsypwzrb_qD2jX9g&ved=0CAQQpitqFQoTCPX9mLS3nsgCFcWaHgodaZYDRQ&ei=uakLVrW9DMW1eumsjqgE

[don_svetlio]

The CX are not meant for GPUs at all - using one with 1 card, let alone 2 is a dangerous endeavour as it can easily overload it's heat tolerance and result in a failed PSU and potentially system damage.

I'd strongly suggest getting a decet 750W PSU such as the EVGA G2/GS, SeaSonic M12II/S12G/G-series, Super Flower Leadex/Golden Greeen or Antec High Current Gamer/Pro/Platinum

750W is all you need for SLI or CF for the most part.

[quan289]

Due to the design of certain power supplies, it is not recommended that you run a GPU on a secondary PSU. Group-regulated power supplies like the Corsair VS/CX, Seasonic S/M12II-B 380-600w and it's rebrands (Antec HCG-400-600 / M, XFX Core Edition / ProSeries / TS 450 / 550w, PCP&C Silencer MKIII 400-600w, etc), Cooler Master B, FSP Aurum Gold / CM, etc. are not design to handle such a load.

 

You are putting zero load on the 3.3/5v and a high, dynamic load on the 12v, in which you are putting the PSU in a crossload scenario where you will see poor voltage regulation.

 

You want to get an independent regulated power supply via dual mag-amp or DC-DC. Something like the Cooler Master GM, Seasonic G / S12G, Corsair CS and above, Seasonic S/M12II B 650w+, Fractal Design Integra M, Antec VPF / Earthwatt Green, etc.

 

TBH, since you will likely going to be buying a new power supply to do this, I would just go ahead and buy a new single PSU that can power you entire system. I'm sure you are able to find an affordable, quality unit in your price range. This way, you don't have a box with dangling wires on your desk (or where ever you are putting it) or the need to buy a case with dual PSU support (which cost money).