I have an NVIDIA RTX 2070 Super and currently use one 4K monitor at 60 Hz, mainly for video editing rather than gaming. I'm buying a 43-inch 4K TV and would like to use it as a second display by duplicating the image from my existing monitor, rather than extending the desktop. Both displays should run at their native 4K resolution and 60 Hz, with the monitor connected over DisplayPort and the TV over HDMI.
Will duplicating the display require substantially more work from the graphics card than using a single monitor? I'm hoping the GPU renders the desktop and applications once, then sends the same output to both displays, so there won't be any noticeable slowdown, stuttering, or reduced responsiveness. My system has a Ryzen 9 3900XT, 128 GB of RAM, and Windows 11. I'd prefer not to keep switching cables or manually changing displays if possible.
3 Answers
The main things to watch are mismatched refresh rates, resolutions, or display modes. A duplicated desktop may be limited to the capabilities of the slower display, and unusual combinations can sometimes cause timing or bandwidth issues. With two 4K/60 displays, the RTX 2070 Super should have no trouble driving them for normal desktop and editing work. Make sure the TV’s HDMI input and cable support 4K at 60 Hz.
Duplicating the same image generally adds very little GPU load, especially when both displays use the same resolution and refresh rate. The GPU renders the frame once and can scan it out to both outputs. Since both of yours will be 4K at 60 Hz, this should be straightforward and you’re unlikely to notice a performance difference.
You shouldn’t need a new graphics card for this. Extending the desktop can require separate display composition, but even that is usually a small overhead compared with rendering video or 3D content. Mirroring is normally even less demanding. If anything behaves oddly, check Windows display settings and the TV’s input mode, since TVs sometimes default to a limited refresh rate or chroma format.

That’s exactly what I was hoping to hear. Both displays will be 4K at 60 Hz, so I’m mainly concerned with avoiding stuttering while working in Adobe applications.