I am seeing the same thing (BIOS 0030, 4GB RAM, Samsung EVO840 120GB). System interrupts gobble up a large portion of CPU. I can already tell that it's going to happen on boot, as the boot itself takes a lot longer than usual.
So far I found that uninstalling the Intel Sideband Fabric device software improves things significantly (down from 60% to 4% CPU on idle). Try it and see if this fixes things for you. If so, the Intel guys can fix their driver.
*EDIT* Success claimed too soon
A simple push on the sleep button, and waking the system up again is enough to trigger the system interrupt issue again. I ran LatencyMon to figure out which driver takes all the CPU, and it turns out to be Wdf01000.sys (Kernel Mode Driver Framework Runtime). It handled close to 8 million interrupts in one minute and used 50% of the CPU. So the big question is, what causes these interrupts.
I have already disabled the internal MMC, the serial ports, onboard audio, HDMI/displayport audio. Still no joy..
Someone at Intel really needs to step in and tell us where to look. I'm more than happy to assist in debugging but this ain't working.
The NUC BIOS team is aware of this issue and are currently working on a BIOS update to fix the problem. I do not yet have an ETA on when to expect it, however.
Thanks for the response, Lois. Good to hear that the problem is known and that your team is working on a solution. Feel free to get in touch if you need a beta version tested in the field.
I see a BIOS 0034 release that has a description 'Fix slow and sluggish response' in the release notes. Does that version address the high system interrupt issue?
Yes, BIOS v0034 fixes this issue.