[coreboot] Lenovo X200 running Coreboot drains 3-4W more power than with Vendor BIOS

[Petrov, Andrey]

Hi,

coreboot as such is not active once your system has booted. My guess is that with vendor BIOS you are getting better working p-states and/or c-state residency than with coreboot. 

I think lower max consumption with vendor bios can be attributed to the cpu really being idle in your experiment. Could you try running stress -c 8 -m 8 on both stock bios and coreboot bios and compare peak consumption? Also what happens if you boot on vendor bios with idle=poll ? this will disable cstates, so if power consumption goes up, that  may be the problem. You can also try with intel_pstate=disable on vendor bios and see if that makes a dent on wattage.

Andrey