On 01.05.2016 21:40, Daniel Kulesz wrote: > Hi again, > > I did some more experiments with the vendor BIOS and made the following > observations: > > - disabling "cpu power management" makes the idle consumption raise to 12,8W Is this 12.8W compared to 7.5W (i.e. with lowest backlight)?
> - disabling "PCI Bus power management" and "PCI express power management" > makes the idle consumption raise to 13,3W > - disabling the AMT firmware had no effect > - running the stress test still drains only 24,2W > - performance is the same as before > > I still don't understand the whole performance issue. Therefore, I took > another X200 with a P8600, CCFL screen and an older vendor BIOS and > re-ran the benchmark there --- with almost identical results. > > So in the end I'm just confused. This would mean that running Coreboot > makes the X200 *much* faster at the expense of battery life, both in > idle and under stress conditions. > Maybe Lenovo limited the processor clock on purpose to get a better battery life. Maybe it's just an unexpected side effect of running Linux (not Windows, what Lenovo tested against). Anyway, I wouldn't care about the power consumption under load, it might even result in a longer battery life: Being faster means shorter periods in higher performance states. The idle power consumption is what really matters. > Any ideas which could solve this mystery? > One more thing you can test, in case your Linux uses the intel_idle driver: There is a kernel parameter intel_idle.max_cstate, if you boot the vendor BIOS with defaults and Linux with intel_idle.max_cstate=2 it should use C1/C2 but not C3/C4 and thus behave more like coreboot. Nico -- coreboot mailing list: [email protected] https://www.coreboot.org/mailman/listinfo/coreboot
