Question How to run my main gaming monitor at it's best refresh rate (120hz) with my flat screen tv as a second monitor

[seecreech]

I have a dual monitor set up. My main is a Benq xl2420z and an insignia 55"ish flat screen for my second monitor. If I game with the flat screen off and set the benq for high refresh rate, I get great performance. But if the tv is on, my computer goes with a lower refresh rate to accommodate the flat screen.. I think. Is there a way to have both on, and have both run at different rates/resolutions?

i5 8400 cooled with a cool master 280 closed unit, gtx 970, 16gb ddr4, z370 aorus ultimate gaming board

displays are set to extend from benq(main) to flat screen(2)

 

[helpstar]

select the settings you want in windows settings for each monitor or like this:

View: https://www.youtube.com/watch?v=i0qNlBnhpDA