[zbrozek]

It's a server motherboard, not a consumer motherboard, so it doesn't surprise me that power management is not great. AMD Rome is also not exactly known for its low idle power.

Looking at powertop, the various qemu virtual machines have high events/sec compared to host processes. There are also a couple of timers - tick_nohz_handler and hrtimer_wakeup - which seem to generate hundreds of events per second.