Table of Contents

Dell PowerEdge R720

https://i.dell.com/sites/csdocuments/Shared-Content_data-Sheets_Documents/ja/jp/Dell-PowerEdge-R720Technical-Guide-2018Jun.pdf

boot speedup

AC loss recovery

Setting not accessible from IDRAC. Need to use IDRAC console, reboot machine and enter to setup (F2). In setup it is possible to setup:

Other possibilities - use Linux software to modify BIOS settings:

idrac syslog

ENERGY_PERF_BIAS

Despite of BIOS setting to performance kernel changes it during boot:

kernel: ENERGY_PERF_BIAS: Set to 'normal', was 'performance'

https://support.scc.suse.com/s/kb/Boot-log-displays-ENERGY-PERF-BIAS-Set-to-normal-was-performance?language=en_US:

The EPB MSR (ENERGY_PERF_BIAS Machine Specific Register) is a feature of some Intel CPUs.  It can be set to a value from 0-15 to tell the CPU (microcode) whether it should prefer performance (0) over powersave (15) power management.
Intel has observed that on many systems after the hardware platform firmware (BIOS/UEFI) finishes initialization, the initial EPB value is 0 ('performance').  While on some systems this is intentional, on others it is due to the system firmware (UEFI/BIOS) not properly initializing the value of the EPB MSR.  Intel implemented a fix in the Linux kernel EPB initialization code to set the EPB to value of 6 ('normal') when the Linux kernel boots.  After the kernel finishes loading a proper EPB value can then be selected.  Unfortunately, this causes a bit of an inconvenience on systems where the system firmware deliberately set EPB to 0 as they will need to set the value back to 0 after Linux loads.  However, other systems (where the EPB value is 0 due to not having been properly initialized) have a higher power consumption than intended/desirable which can cause issues for systems operating from battery power (standby/ups power, or laptops).

ENERGY_PERF_BIAS:

apt instal linux-cpupower
 
# x86_energy_perf_policy
cpu0: EPB 6
cpu1: EPB 6
...
cpu30: EPB 6
cpu31: EPB 6
 
# x86_energy_perf_policy balance-performance
ipmitool sensor reading 'Pwr Consumption'