The only way to get it to run at full speed in every game is to use a heavily overclocked sandy bridge i5 or i7. You may get acceptable speeds with AMD hardware, but usually you can say a 4.5 GHz AMD CPU is equivalent to a 3GHz Sandy bridge one. So far I've been fine with 3GHz of i5, so if you can squeeze 4.5 GHz into your motherboard you should be satisfied until you go for the most demanding of games. It'll also be much cheaper for similar performance as long as you overclock it enough. However if I was in your situation I would go for the Intel option, as it would be the largest speed increase.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56