Yeah I would reduce the voltage/speed rather than disable cores if possible. All I have messed with are i5's and i7's but with those you can just reduce the multiplier and/or turn off turbo if you dont want to mess with figuring out a stable voltage.
Yes got it about laptops generally. Will also try other less energy using cryptos.
I am now using older PC. So, how does the multiplier get reduced and /or turn off the turbo?