bill holler wrote: >>> >>> PowerTOP should not be the case that causes 100% highest p-state >>> residency in idle. We have this bug >>> "6818514 Event based CPUPM too easily shifts into high gear" >>> >>> fixed and putback since build 117 by rev#. 9802. It looks like it >>> does not >>> fix the problem. >> I believe it does, at least for a i7 920 based system: >> >> OpenSolaris PowerTOP version 1.2 >> >> C-states (idle power) Avg Residency P-states (frequencies) >> C0 (cpu running) (0.6%) 1596 Mhz 100.0% >> C1 3.9ms (99.4%) 1729 Mhz 0.0% > > > Hi, > > It looks like C-states are disabled in BIOS on this i7-920? > You definitely want C-state enabled on i7 for power savings. The C-states are set to "Auto" in the SBIOS, for which the comment says something about deciding based on the capabilities of the CPU and the motherboard (eVGA X58 SLI). Latest SBIOS is installed.
The SBIOS also has explicit options for enabling deep C-states beyond just C1: (Auto, C1, C1E, C3, C6). However, when I enable any of these I still only get C1 in the powertop output. I have also added "cpu_deep_idle default" to /etc/power.conf but that didn't change the behavior.
