I have tried all the suggestions here How to disable CPU frequency scaling in CentOS 6?
However, the frequency still changes up and down. Even for CPUs I have isolated which are idle.
$ grep "cpu MHz" /proc/cpuinfo cpu MHz : 3201.523 cpu MHz : 2197.091 cpu MHz : 3575.810 cpu MHz : 3521.169 cpu MHz : 1675.158 cpu MHz : 3559.854 cpu MHz : 3079.546 cpu MHz : 3092.115
$ grep "cpu MHz" /proc/cpuinfo cpu MHz : 2791.615 cpu MHz : 3006.516 cpu MHz : 2203.565 cpu MHz : 2030.085 cpu MHz : 1774.537 cpu MHz : 3591.576 cpu MHz : 3600.343 cpu MHz : 3595.899
NOTE: the last two CPUs are isolated so basically idle at this time.
I have tried setting the BIOS to maximum speed and normal. I have tried all the governors and turning intel_pstates on and off.
$ cpupower frequency-info analyzing CPU 0: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 10.0 us hardware limits: 1.20 GHz - 3.60 GHz available frequency steps: 3.60 GHz, 3.60 GHz, 3.40 GHz, 3.30 GHz, 3.10 GHz, 2.90 GHz, 2.70 GHz, 2.60 GHz, 2.40 GHz, 2.20 GHz, 2.10 GHz, 1.90 GHz, 1.70 GHz, 1.50 GHz, 1.40 GHz, 1.20 GHz available cpufreq governors: conservative userspace powersave ondemand performance schedutil current policy: frequency should be within 3.60 GHz and 3.60 GHz. The governor "userspace" may decide which speed to use within this range. current CPU frequency: Unable to call hardware current CPU frequency: 2.02 GHz (asserted by call to kernel) boost state support: Supported: yes Active: yes
The current speed is usually less than the minimum, however, I have seen it as 4.0 - 4.3 GHz.