> I also like my old car and I'll keep it as long as I can but I'm aware a new one would be much more fuel efficient.
From what I see of comparable-model cars, efficiency gains in engines, aerodynamics, etc. have mostly been offset by safety, emissions, and QoL improvements that have increased weight. For instance, by spec, the most fuel-efficient Corolla was a 1984 model.
Do note the note at the bottom of the table: "Note: the EPA tweaked their testing procedure, starting with the 2008 model year, with the end result being that the 2008 MPG estimates are now lower than previous years"
Other compact cars have followed a similar trend where they've gotten much heavier and safer, but fuel economy (in terms of fuel per distance) peaked or stagnated.
That's only really relevant for 24/7 operations with considerable load. For home computers and probably even servers with very little load the price of a new CPU won't really offset lower electricity cost.
Depends on whether you switch them on and off to follow load. Newer chips/systems have better idle characteristics so if the system is always on,its probably worth it to upgrade for that reason alone.
Talking about cars: first car was most economical one, second one consumed more because of catalytic converter. Third one is a car for fun not for commuting with massive fuel consumption.
Old FX-8350 was available for this one shot Linux project. Normally virtual machine is ok. I had lots of thoughts what I do with good old hardware when upgrading to Ryzen, I delayed it for more than a year. Luckily it was solved this fortunate way and I do not need throw working things away.
I also like my old car and I'll keep it as long as I can but I'm aware a new one would be much more fuel efficient.