How to determine metric of how smoothly a game will run?

I hear a lot of people discussing on streams how using different plugin, assets and setups can differently affect the performance of a game. I know this is important however I’m not sure what metrics I should looking at or what tools people use to figure out the impact of different development choices they make.

Does anyone know a good article I could start by looking at?

What metrics does everybody use? Are there any specific optimisation / benchmarking tools?

Unreal Engine has a profiler which will tell you all about how much impact things have, but in terms of checking to see how well things perform for system requirements the best thing to do is test on multiple machines, it helps to have a machine for testing that is your minimum requirements so that you can test on there during development and optimize for that.

Thanks DarthViper107, I’ll check that out.