FPS drop after GeForce 680 SLI installment

[Alexander_Ohman]

Hola!

I've recently bought myself a second GPU, but after I installed it I'm getting huge FPS drops in CS GO as well as the game is not running smooth anymore. Same with Fallout 4, very laggy..
I've tried swopping drivers - didn't work. Tried one card at a time, every game runs great. But when they're both installed, I keep on getting those FPS drops.
Can it be power related maybe?

Hit me with your ideas!

GPU: EVGA GeForce GTX 680
CPU: Intel Core i7 3770 - 3.40GHz
RAM: 16GB 1333 Mhz
MOTHER: Gigabyte G1.Sniper M3
PSU: NZXT 750W

 

[r21g2017]

I would make sure you have identical Video cards first and if that checks out I would update the bios and Nvidia drivers.

 

[Alexander_Ohman]

I would make sure you have identical Video cards first and if that checks out I would update the bios and Nvidia drivers.

200% sure that I have identical video cards, and I've played around with different drivers, both the latest and older version of Nvidia drivers. Haven't tried the bios drivers though.