Groovy MiSter is a project that allows you to use your MiSTer FPGA as a video card that connects your PC to a CRT. This is done over a network, but latency is actually very good. The project Github mentions a latency of around 3ms and in my testing for most games, the CRT output from the MiSTer was faster than the local output of the PC monitor. This is because supported emulators are bypassing the SDL video renderer and sending pixels as soon as a frame is available. This avoids any overhead that maybe introduced with graphics API’s and drivers.
Another advantage of using GroovyMAME is that you can now play games and systems that are unsupported on the MiSTer FPGA on a CRT. So games like Golden Axe: The Revenge of Death Adder, Mortal Kombat 2 and so many more are no longer out of reach. You are only limited by the power of your PC. Emulators supported are MAME, Retroarch and Mednafen. The above video demonstrates how to use Groovy MiSTer and what you can expect from it.