powerd vs hwpstate_intel on a CPU with Intel Speed Shift

D

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My desktop computer has an Intel CPU that supports Intel Speed Shift.

Code: 
# sysctl dev.cpufreq.0.freq_driver
dev.cpufreq.0.freq_driver: hwpstate_intel0

If the computer is using the hwpstate_intel driver, does it mean that the computer has no need to run powerd? Does it mean that I should remove powerd_enable="YES" from my /etc/rc.conf?
 
driesm said:
That's correct :)
Click to expand...

Thank you for the confirmation.

Does this mean that if I want maximum energy savings, I should add the following lines to /etc/sysctl.conf?

Code: 
# Assuming that the CPU has 12 threads.
dev.hwpstate_intel.0.epp=100
dev.hwpstate_intel.1.epp=100
dev.hwpstate_intel.2.epp=100
dev.hwpstate_intel.3.epp=100
dev.hwpstate_intel.4.epp=100
dev.hwpstate_intel.5.epp=100
dev.hwpstate_intel.6.epp=100
dev.hwpstate_intel.7.epp=100
dev.hwpstate_intel.8.epp=100
dev.hwpstate_intel.9.epp=100
dev.hwpstate_intel.10.epp=100
dev.hwpstate_intel.11.epp=100

Is that all? I would have thought that there would be more settings, like in powerd.
 
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Reactions: mro
thanks for the deep link,

mr123 said:
This is mentioned in the handbook section about Intel Speed Shift™ (https://docs.freebsd.org/en/books/handbook/config/#hwpstate_intel):
Click to expand...
I shied away from the rabbit hole named kernel compilation so far, but guess

Code: 
$ sysctl dev.cpufreq.0.freq_driver
dev.cpufreq.0.freq_driver: est0

means I'll have to jump in on my FreeBSD 13.2 Thinkpad x250, do I? Or is there another way to activate it?

Code: 
$ dmesg -a
…
CPU: Intel(R) Core(TM) i5-5300U CPU @ 2.30GHz (2294.82-MHz K8-class CPU)
  Origin="GenuineIntel"  Id=0x306d4  Family=0x6  Model=0x3d  Stepping=4
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Features2=0x7ffafbff<SSE3,PCLMULQDQ,DTES64,MON,DS_CPL,VMX,SMX,EST,TM2,SSSE3,SDBG,FMA,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,TSCDLT,AESNI,XSAVE,OSXSAVE,AVX,F16C,RDRAND>
  AMD Features=0x2c100800<SYSCALL,NX,Page1GB,RDTSCP,LM>
  AMD Features2=0x121<LAHF,ABM,Prefetch>
  Structured Extended Features=0x21c2fbb<FSGSBASE,TSCADJ,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,NFPUSG,RDSEED,ADX,SMAP,PROCTRACE>
  Structured Extended Features3=0x9c000600<MCUOPT,MD_CLEAR,IBPB,STIBP,L1DFL,SSBD>
  XSAVE Features=0x1<XSAVEOPT>
  VT-x: PAT,HLT,MTF,PAUSE,EPT,UG,VPID
  TSC: P-state invariant, performance statistics
real memory  = 8589934592 (8192 MB)
avail memory = 7959314432 (7590 MB)
Event timer "LAPIC" quality 600
ACPI APIC Table: <LENOVO TP-N10  >
…
 
mro said:
I shied away from the rabbit hole named kernel compilation so far, but guess

Code: 
$ sysctl dev.cpufreq.0.freq_driver
dev.cpufreq.0.freq_driver: est0
means I'll have to jump in on my FreeBSD 13.2 Thinkpad x250, do I? Or is there another way to activate it?

Code: 
$ dmesg -a
…
CPU: Intel(R) Core(TM) i5-5300U CPU @ 2.30GHz (2294.82-MHz K8-class CPU)
Click to expand...

X250 is Intel "5th generation", but Speed Shift tech was only introduced on 6th generation processors, Skylake and later.

[edit] While Windows-based, I think this article from 2015 fairly well describes it.
 
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