Two different Graphic Card softwares?

[Revsn]

Hey there everyone, My friend recently got dual 960's in his computer. We started up the computer and the computer loaded fine like normal. We went into Nvidia settings and turned of SLI and even bench marked a few games that were pretty intensive. Fast forward 3 months and now all the sudden its running extremely slow and he can barely run games on low which lag and turbulence. The cards are physically the same(Nvidia GTX 960 4GB), but they are just different brands. So do I need to install the other graphics driver for the second card thats different than the first. Or is there just something wrong with the computer?

Thanks, Revsn.

LINKS:
[First Graphics Card:] https://www.amazon.com/MSI-GAMING-GTX-960-4G/dp/B00V4HY522/ref=sr_1_1?s=pc&ie=UTF8&qid=1476074801&sr=1-1&keywords=msi+gtx+960

[Second Card:] https://www.amazon.com/MSI-GTX-960-OC-4GD5T/dp/B011S6GUCQ/ref=sr_1_8?s=pc&ie=UTF8&qid=1476074770&sr=1-8&keywords=msi+gtx+960

 

[chegalhavara]

I think that wouldnt be a problem. They have same GPU, and that´s the important thing but the faster card will throttle down to match the speed of the slower one, I think.
But I have no experience with SLI myself. Perhaps someone else can help you better.
Did he test the cards individually? One of them might have a problem.

 

[Mousemonkey]

With SLi both cards use the same single driver, you don't have to install a second driver for the second card.