Are you joking? I’m trying to decide whether this merits a serious response. Even if it’s joking, I guess I’ll address it for anyone else who falls into this trap.
You can throw 200 threads at a problem and it won’t help a bit if your code’s only written to run on one thread. Quite a bit of code is written to use only one core because thread safety can be a huge pain, even for relatively common tasks. A better question, then, is how fast each core is, because that’s where you start to actually perceive performance gains for most tasks.
So, both the 2012 and 2014 Mac minis had three processor options. For each, the 2014 Mac mini has about 5% higher single-core performance per Geekbench 5. It’s not night and day, but the 2014 Mac mini is faster per core. Therefore, it should feel modestly faster.