It's fine to have a dual machine, but a couple things to understand:

To get the most out of your GPU, you will need to BIOS mod it, and potentially use different drivers, plus overclocking it for mining. All of these things are not really something you can do while also using that GPU for gaming, at least I wouldnt recommend it.

If you are fine not having an optimized card, just keep in mind you will drastically reduce the lifespan of the card, and may see some issues while gaming. Heat may also quickly become an issue in a standard closed gaming case.