Is it necessary to change the governor in Ubuntu Server 16.04?

Question

I manage a dedicated remote SuperMicro SYS-2028TP-HC1R server with two Octa-Core E5-2620 V4 2.1GHz processors (HT, 32 threads), 32 GB RAM, 2 SDD of 480GB in RAID 1, running Ubuntu Server 16.04, and do not have BIOS access.

When I consult the governor with the command

cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

It shows me powersave.

I require the highest processing speed for MySQL Server 5.7 running on this server, so I don't know if it's necessary to change the governor to performance or another, or leave it like this.

Answer 1

You should just try it both ways. It'll cost you some energy if you use the performance governor instead of the default (for the intel_pstate scaling driver) powersave, but the response time will be a little better.

You can manage things with the basic primitive commands rather than higher level tools. As sudo do:

# for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo "powersave" > $file; done

or

# for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo "performance" > $file; done

Now, if for some reason, you need your system to be able to respond incredibly quickly from an idle state, then consider disabling the deepest idle states, but be aware that it definitely costs energy. I do not know your deepest idle state, this example is for my processor, where idle state 4 is the deepest. Again as sudo:

# for file in /sys/devices/system/cpu/cpu*/cpuidle/state4/disable; do echo "1" > $file; done

For my system, when idle, the cost is 25% more processor package power.

Answer 2

I sure would. You can do that in your BIOS, if you have access to it, which you launch with F2 after the POST completes.

A good description of your options is shown at

https://www.thomas-krenn.com/en/wiki/Disable_CPU_Power_Saving_Management_in_BIOS

Once you get into the BIOS/Firmware settings, choose

-> Advanced CPU Configuration
-> Advanced Power Management Configuration

Change Power Technology to Custom and 
Energy Efficient Turbo to Disable.

Switch to CPU P State Control, 
deactivate EIST (P-States) and 
Turbo Mode.

Then switch to CPU C State Control, 
change Package C State Limit to C0/C1 state and 
deactivate CPU C3 Report, CPU C6 Report and Enhanced Halt State (C1E).

Then, save and exit from the BIOS and boot.