According to
the benchmarks, even the Ryzen 7 3700X is only ~35% faster (up to 4 cores) than your current CPU, and the 3600 is ~25% faster. I'm rocking the i5-3470 and I think they're awesome!
9400GT, booooo. No wonder you want a whole new computer... I've got a spare RX470 4GB if you want an NZG special. Save your money, fix your car, donate to a social service of your choice, or get some pro tier corn chips instead :P
Or not, I don't particularly care.