My building has a really poor network topology. Or no topology at all, just a mess. One day, I plugged in my laptop to my ethernet socket. I noticed it got war

My building has a really poor network topology. Or no topology at all, just a mess. One day, I plugged in my laptop to my ethernet socket. I noticed it got warm very quickly. After some thinking, I monitored network traffic and noticed the frequency of useless broadcast messages due to an incorrectly designed network is absolutely amazing. Using powertop, I estimated this leads to 2 W of wasted energy due to frequent wakeups. Given we have hundreds of computers in the building, I can imagine the waste is not negligible. Same thing applies to a misconfigured desktop. I can save 1.5 W by running a tiling window manager and no desktop environment. I can imagine that tweaking GCC flags could even bring this number down. But just sane configuration does wonders.