Program to capture a screen in another window

[Dreigo42]

Hey Interwebs, I'm trying to find a program that will capture my main monitor and display it full screen on another. But first, let me explain my reasoning.

 

I have my 144hz gaming monitor w/ variable refresh and my Elgato HD 60s Capture card. I want to capture my main screen using the capture card as it provides the best quality. Unfortunately, when mirrored in Windows, I'm stuck at 60hz due to the HDMI connection. So my plan is to use a program like OBS that can capture my main screen and display it full screen to the capture card. This way my displays are extended, not mirrored so I get my full 144hz and variable refresh. Problem is that the preview in OBS can become choppy when it's not the window in focus. Does anyone else know of another program that's lighter than OBS that can do this?

[Electronics Wizardy]

why not just use obs or something like shadow play to capture the game. No reason to use a capture card.

[Dreigo42]

1 minute ago, Electronics Wizardy said:

why not just use obs or something like shadow play to capture the game. No reason to use a capture card.

Because I'm using a second machine to actually record the footage. I've tried OBS and other local software recording and it has never looked as good as a hardware solution.