I do remember IRR calcs on an HP-12C taking a few seconds, or so. And that machine is not cheap either.
That being said, who's running IRR on a pocket calculator?
Back in high school I regularly hit integrations that took minutes to do on my TI-89.
https://www.youtube.com/watch?v=SoDkeg166xU
maybe not the TI-89 which ran 68K processor.
I do remember IRR calcs on an HP-12C taking a few seconds, or so. And that machine is not cheap either.
That being said, who's running IRR on a pocket calculator?