Hooking up monitor to Gpu and motherbored

[LordTourettes]

hello I hooked up my gtx970 to one moniter and run high end games on that moniter on the other I hooked up my other moniter to my mother bored because I stream on it. I thought that if I did that it would take off some stress on my gtx 970 how ever should I just plug them both into my gtx970 would that slow my other games down and on screen resolution both of the input signals just say the model of my moniter not the input of my gpu or mother bored is that normal aswell with the pros and cons of plugging in both monitors in my gpu or leaving one in my gpu and one in my motherbored thx

 

[i7Baby]

should I just plug them both into my gtx970 - Yes

would that slow my other games down - maybe a bit

I don't understand the last bit.