I'm curious - for power consumption, considering that you can get RaspPi products for so cheaply, is a discarded laptop more or less impactful on your electrical bill than a RaspPi?

Like is the "free" laptop going to cost you more in the long-run then a nice little power-sipping ARM like a Pi5? Or do you need those extra operations-per-second that the more power-hungry x86 CPU gets you?