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On 12/16/2016 07:13 PM, Taiidan@gmx.com wrote:
y'all helpful as always >:D
On 12/12/2016 03:00 PM, Timothy Pearson wrote:
On 12/11/2016 07:52 PM, Taiidan@gmx.com wrote:
Thanks! helpful as always >:D Yes c states and cc6 states are enabled, 1 or 2 cores can get up to around 100mhz or so less than turbo 2 however I cannot get the whole advertised 8 or even 4 (i get max around 2.5ghz as reported by "cpupower monitor" ), my temp is 35C with full load cpu usage and my fans nearly off (tower cooler) so I don't think that could be the issue.
Interesting. Are these the results of the turbostat program? What does powertop show in the idle stats?
Powertop, around 96-98% or so. Turbostat doesn't show turbo frequencies for some reason under tsc_mhz, and average cpu freq is lower than wcpupower monitor reports.
With a single 100% cpu thread I can get to 3ghz (still a little short), however with every thread I add the clock speed goes slightly down. Weird stuff.
I strongly suspect Linux is scheduling threads on the other cores, causing the black box inside the CPU to momentarily take the highly loaded CPU(s) out of maximum boost for brief intervals. turbostat and friends work by measuring the TSC over a period of time to detect boosted operation, and being "a little short" of maximum boost is consistent with this theory.
Is there a way to view and force c-states? I tried using turionpowercontrol but it didn't work, the cpu simply clocked up again and it only has a max cstate and not a min cstate option. I am curious is there a way to disable the second half of the 16 core CPU optys in coreboot?
No, you cannot force C-states with a stock kernel. Coreboot itself has no control over this; the Linux kernel controls all power saving states across all cores once started. One thing you can try is to move all of your processes (including system processes) onto one group of cores with cgroup functionality; Linux should then idle the unused cores via the C3 (subsequently hardware-transitioned to CC6) power saving state.
- -- Timothy Pearson Raptor Engineering +1 (415) 727-8645 (direct line) +1 (512) 690-0200 (switchboard) https://www.raptorengineering.com