Will mirroring my screen to a TV that is set to another input hurt graphical performance?


Jan 20, 2018
Recently I was given a 37" Vizio E370VA TV, and I have it hooked up to my computer via an HDMI cable. I set it to mirror my main monitor's display in the windows display settings. The TV is also wired into a few other things, including my satellite TV and an old Apple TV.

If I select the HDMI input that my computer is plugged in to (so my main monitor's screen is showing up on the TV), obviously my PC's performance in games will be affected. However, if I set my TV to another input (the Satellite or Apple TV), will my PC still be affected? In other words, will my GPU still try to draw my main screen on the TV if that input isn't selected on the TV? Or will I have to unplug the HDMI cable running from my computer to the TV whenever I want to do play games or do anything that is GPU intensive?

I have a good amount of experience working with computers but I know pretty much nothing about TVs. The PC is around a year old and has a 1070, so it shouldn't have any problem pushing all of those pixels if I'm just browsing forums or watching youtube. Thanks in advance


Jan 22, 2009
I'm not an expert on this topic so my assumption may be wrong.

I think it is reasonable to assume that calculation of pixels is done prior to sending the information further to the hdmi output. I also assume that when OS tells the graphic card to clone the output, then the output (both dvi out) get the common picture information, after calculation of pixels.

If all those assumptions is correct, then the graphic card should not have any performance hit.

Hower - why ask here if you can download a GPU benchmark program and conduct a test for yourself, one test for one screen and another with mirrored screen. That will answer your question. Feel free to post your conclusion. . .