Nothing affects frame rate quite as much as your graphics card. But which GPU? Which manufacturer? Which clock/memory configuration? All of these factors come into play – making the difference between choppy frames and silky smooth action.
Despite being the cheapest of Nvidia's RTX cards, the RTX 2060 Founders Edition is a great buy. It has enough Turing shaders to out-muscle the Pascal-based GTX 1070 Ti, and does so while dropping the price to £329. There's even enough RT cores to get playable frame rates at 1080p with real-time ray tracing enabled. If you want a great gaming experience, with or without RTX, the 2060 is the way to go.