Will mirroring monitors cause performance impact or glitches?

Question

Basicly, I am trying to streaming. I hame a HDMI capture card which takes only 1080p 60Hz. Also, I have a monitor runs at 1080p 144Hz.

I cant just connect my monitor to the capture device, because in that way, it will not run at 144Hz. In FPS games, that refresh rate do make a difference to me.

So I configure the two 'monitors' (one of them is a capture device) as mirrored. One of them runs at 144Hz, the other one at 60Hz.

Everything seems fine. But when I run the popular UFO test, it seems to be unable to determin my refreshrate (it says UNABLE TO SYNC).

Also, my game (Apex Legends) seems to have a lower framerate. I'm not sure if it is the update or my mirroring configuration.

Will this difference in refresh rate of the mirrored monitor hit the performance or cause glitches?

If so, what is the proper way to achieve the same thing (output to two monitor running at different refreshrate the same image without hitting the performance)?

EDIT: I found a similar post here ,but I can not simply set my hdmi output (to capture device) to 144Hz. If I do that, my graphics card will actually output at 144Hz, and my capture device will capture nothing.

Answer 1

I located the problem.

The answer to the problem might be:
Mirroring the two monitors as said in the question would not cause major performance impact or glitches, at least for my setup now.

It is my laptop. I am using a recently bought power supply, it does not meet the power requirements.