I've been trying to optimize my desktop's power consumption. At the beginning of the year I put the kill-a-watt on it and was shocked to see it was using 115W idle! I got it to 90W pretty quickly with some minor Linux tuning but was still pretty unhappy to see so much idle load. Recently though, I've got it idling at 57W, which makes me feel much better about it (although more than I'd want for a 24/7 load). 5700X cpu and RDNA4 9070XT video card.
Dialing down unnecessary cooling helped more than I would have guessed. Under-volting the GPU -30mV may have helped but I'm not sure. Adjusting every governor I could find to powersave helps of course, and doesn't feel noticeably different. A lot I think is just that the new tuned daemon is way way way better at it's job than previous solutions like tlp was. I did have some problems with my Crucial P3+ NVMe drive not liking "powersupersave" PCIe Active State Power Management (aspm), but most improvements were a kernel setting away, and tuned really seemed to do .
One of the thing I really love about modern computing is that I can just dial in power consumption under load. With the new RDNA4 video card, I was seeing 450W power consumption when gaming. But I can open CoreCtrl and tell it, no, use 70W, and for surprisingly little FPS hit my system is now down to ~155W. (Still looking for more control in Linux for the CPU!)
It is lovely that there are all these mini-PC's, many of which will idle at ~10W! But definitely worth noting that power consumption on desktop is much more configurable than it used to be.