ShaderBeam provides CRT-like motion clarity on high refresh rate LCD and OLED monitors — open-source project offers BFI emulation in any game

Yes

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One of the overlay's most interesting quirks is the developer's recommendation to run two GPUs. Dedicating one GPU to just running the CRT emulation GPU shader allegedly eliminates a lot of desync issues in most games compared to running everything on one dedicated graphics card (even if that graphics card is very quick, apparently). Luckily, the GPU shader portion is extremely lightweight, and even an old Intel HD 770 can allegedly run the shader at well over 800 FPS at 1080p. This will be an annoying quirk gamers with no integrated graphics chips will have to deal with (particularly AM4-based Ryzen users)

The recommendation is not necessarily to run two dedicated GPUs, it is to have an additional GPU (including iGPU) to dedicate to running the shader.

Use of the word “dedicate” made that a bit confusing since that is common terminology for discrete GPUs