I agree. I don't feel much difference between the 15" MB-Pro i7 4-core from 2014 and the i9 8-core from 2019. The i9 really isn't noticeable faster on single core. Instead it gets hotter and its fans starts sooner. So I recommend keeping the old one if you have it.
Wouldn't newer ones be more power-efficient as compared to the older one? I remember reading a post on HN which stated the OP buying older, high spec hardware for cheaper than latest one and almost all comments pointed to power-efficient thing
From what I see the problem is that the newer Macbooks are slimmer and have less efficient thermals. So the processors are more efficient, but the benefit gets lost by shipping them in smaller enclosures and on top of that smaller batteries.
I'd love to see the new processors and RAM in a 2015 enclosure. Makes me wonder whether someone has attempted to hack it together.
The dGPU is much hotter due to a no-downclocking driver bug that is worse on a chip that is more powerful, and bad software that wastes CPU cycles had more cycles to waste.
Yes, of course. Processors are idle most of the time anyway, but single processor has more time to dissipate heat passively doing same amount of work (e.g. 2% work, 98% idle), while multiple processors, e.g. 4, will use same amount of energy 4x faster (0.5% work, 99.5% idle), so fan will kick in.
