I have a Proxmox server running two Opteron 6272 CPUs on an Asus KGPE-D16 (chosen because it was the fastest computer that supported Libreboot, although I haven’t gotten around to installing it). Using normal BIOS settings, it’s drawing just under 100W at idle, measured via smart plug reported in Home Assistant. With aggressive efficiency settings (PowerCap to P-state 4 and disabling CPU 2 entirely) it idles at 70W. It’s a server, not a gaming PC, so it doesn’t appear to have any options for underclocking or adjusting voltage.
Anybody know of any other ways (maybe software-based) to get the power draw down further?
Those old server CPUs and motherboards just draw a ton of power, I’m not sure there’s much more you can do.
It might be best to change hardware if you need lower power draw, a $50 PC off ebay with an i5-7500 should be faster and a only uses about 15W idle.
4 cores worth of Kaby Lake is faster than 32 cores worth of Interlagos?
Well definitely faster than 1 Opteron at least: https://www.cpubenchmark.net/compare/1569vs2910/AMD-Opteron-6272-vs-Intel-i5-7500
Single thread is massively better, but if that’s useful or not depends on the kinds of applications you’re running.
OP seems to be looking for LibreBoot compatibility, so it might not be as easy.