I've been satisfied with NanoKVM lite. Cheap and does what i want.

I have the PCIe version of NanoKVM, and I am also happy with it.

The big advantage of the PCIe version is that it does not take up space on the desk and all the cables for ATX power control an inside the PC case.

Full-sized HDMI is nice, the only limitation here is 1080p resolution. 1440p or higher would allow mirroring the output on the main monitor to the NanoKVM, but this probably a weird use-case anyway.

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