HDMI splitter to mirror a monitor to a TV

[wp7456]

I have a 2 monitor set-up. I recently bought an hdmi splitter so that I can mirror the screen on one monitor to a nearby television. Only one small issue though - it forces the monitor that's connected to the splitter to have a slightly larger resolution and becomes a little pixelated. It's kind of annoying going from one monitor to the other when they are not perfectly identical. Any way to fix this?

 

[USAFRet]

From an HDMI splitter, the PC only sees one monitor. Hence, one resolution setting.

 

[wp7456]

From an HDMI splitter, the PC only sees one monitor. Hence, one resolution setting.

What would be the next best way to set it up? Buy a GPU that has 3 slots and then use the TV as a 3rd separate monitor but change the settings in windows when I want to switch to mirrored mode?