Solved Difference between Max Processor State and Max Processor Frequency

I became aware of the great power settings tweaking tool 'Power Settings Explorer' ( Windows power plan settings explorer utility ). It allows you to hide/unhide, and change, many different settings related to power plan settings.

I've been aware of 'Max Processor State' for a long time; you specify it in %, from 0-100%. But through this new tool, I became aware of 'Max Processor Frequency', which you specify in Hz, from 0-<your maximum frequency>.

My question is - if I set 'max processor state' to, say, 50%, what am I actually limiting - is it affecting a voltage, a frequency, or what?

Thanks for any insight. Google doesn't seem to be helping me on this one!

May I ask why you would want to? What are you trying to accomplish? Underpowering a cpu will affect performance, at 50% it will be greatly affected. For overall balance of performance vs power consumption, you should use the balanced power plan.

If your aim is to reduce heat, the i7-1065G7 gives the option in bios to disable hyperthreading. Without hyperthreading, your processor gets one program per core at a time. Hyperthreading means you can get multiple programs per CPU, which allows you to basically turn each core into two processors. Your particular CPU has 4 cores and 8 threads.
If you use you laptop for nothing more than email and web browsing, disabling hyperthreading probably would not affect its overall performance. However, if you use applications requiring more processing power, you would notice performance loss.

That particular cpu is a power efficient cpu in the first place, averaging only 15W. IMO, it is inadvisable to mess with its power setting.

glasskuter said:

May I ask why you would want to? What are you trying to accomplish? Underpowering a cpu will affect performance, at 50% it will be greatly affected. For overall balance of performance vs power consumption, you should use the balanced power plan.

If your aim is to reduce heat, the i7-1065G7 gives the option in bios to disable hyperthreading. Without hyperthreading, your processor gets one program per core at a time. Hyperthreading means you can get multiple programs per CPU, which allows you to basically turn each core into two processors. Your particular CPU has 4 cores and 8 threads.
If you use you laptop for nothing more than email and web browsing, disabling hyperthreading probably would not affect its overall performance. However, if you use applications requiring more processing power, you would notice performance loss.

That particular cpu is a power efficient cpu in the first place, averaging only 15W. IMO, it is inadvisable to mess with its power setting.

Click to expand...

I'm primarily asking a question about units of measure, not computer strategy - one of the settings I mention is in units of frequency (Hz) while the other is in units of 'percentage'. I'm asking what actual, underlying physical adjustment takes place when you set a percentage below 100%; is it voltage, frequency, or something else? I used '50%' as a simple example to frame the question; I have no intention of setting it to 50%. I want to know, when I set 50%, what 'thing' is halved - the frequency, the voltage applied to the CPU, or what?

Now - as to why I would want to adjust it, there are many reasons. I personally happen to be extremely sensitive to fan noise, and I have long used that setting (max processor state) to reduce overall CPU power in order to guarantee that the fan does not kick in. Even setting it to 99% is known to disable 'turbo' mode, which will stop temperature spikes and therefore fan activity. On my last laptop I found that setting max processor state to 75% would prevent the fan from ever kicking in, while having no noticeable impact on actual, real-world perceived performance during my daily activities (browsing, spreadsheets, excel, email, quicken, etc). When I need to transcode a video or play a game, I can set it to 100% in seconds.

But now I'm aware of the 'max processor frequency' setting, I'm considering experimenting with it for similar purposes (and other purposes). But it then occurred to me - being an engineer and all - what is 'max processor state' actually adjusting?

TL;DR - what underlying physical component (frequency, voltage, etc) does 'max processor state' adjust?

I am not a hardware expert but here's the way I understand it. If I am wrong, I hope someone will correct me.

Min/Max Processor states:
These 2 options customize your clock speed. The clock speed measures the number of cycles your CPU executes per second in GHz. This basically means the speed of your cpu.
If you reduce your Max Processor State you would be using less power but sacrificing performance.
The Minimum Processor State specifies the minimum frequency the computer is running while performing minimal tasks or idling. (ie the constant speed of cpu) Changing this will vary the processor's clock speed and, if supported, voltage and FSB speed.

Intel's explanation of clock speed here CPU Speed: What Is CPU Clock Speed? | Intel

I forgot to say that Max processor frequency specifies the operating frequency of the CPU core(s)

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Just a sidenote: Hyperthreading gives only about 25% performance gain per core. This is on a good day (an app that runs code that can easily be vectorized), most often you only gain about 15% performance, if any.

In worst case scenario, your apps will run slower when HT is enabled. This happen rarely though, but is possible.

Steerpike said:

I've been aware of 'Max Processor State' for a long time; you specify it in %, from 0-100%. But through this new tool, I became aware of 'Max Processor Frequency', which you specify in Hz, from 0-<your maximum frequency>.

Click to expand...

According to the definition MS published in Power Policy Configuration and Deployment in Windows dated 21st October 2010, Max processor state is simply the percentage of max processor frequency i.e. these two things are not independent parameters at all.

MS never updated this document & stopped making it available years ago.

There are current references in
"MaxFrequency specifies the maximum processor performance state, which is specified in Megahertz (MHz)."

If you are going to investigate these parameters using PowerCfg then note that you will need to include listing of hidden properties using the -qh switch instead of the simple -q switch.
That 2010 document also happens to be the only place I've seen the -qh switch documented.




Denis

Try3 said:

According to the definition MS published in Power Policy Configuration and Deployment in Windows dated 21st October 2010, Max processor state is simply the percentage of max processor frequency i.e. these two things are not independent parameters at all.

Maximum Processor State Setting
Description	Specifies the maximum processor performance state. The performance state is specified as a percentage of maximum processor frequency.
GUID	bc5038f7-23e0-4960-96da-33abaf5935ec
PowerCfg Alias	PROCTHROTTLEMAX
Minimum Value	0
Maximum Value	100
Label	Percentage (%)
Hidden	No
Operating System Versions	Available in Windows Vista and later versions of Windows.

MS never updated this document & stopped making it available years ago.

There are current references in

MaxPerformance

MaxPerformance specifies the maximum processor performance state, which is specified as a percentage of maximum processor performance.

docs.microsoft.com

MaxFrequency

MaxFrequency specifies the maximum processor performance state, which is specified in Megahertz (MHz).

docs.microsoft.com

"MaxFrequency specifies the maximum processor performance state, which is specified in Megahertz (MHz)."


Denis

Click to expand...

Thanks! This is what I was looking for: "The performance state is specified as a percentage of maximum processor frequency." So the two settings just give you two ways to achieve the same end result - a reduced processor frequency. By allowing it to be specified as a %, you don't have to concern yourself with your particular processor's specific values. So really, I can see no particular value to using 'Max Processor Frequency' (which is probably why it's not well publicized).

I'm glad to be helpful.

I was still fiddling about adding a para about using PowerCfg at the end which you might not have seen.

All the best,
Denis

I tracked down a current download link for Power Policy Configuration and Deployment in Windows dated 21st October 2010.

Denis

Try3 said:

I'm glad to be helpful.

I was still fiddling about adding a para about using PowerCfg at the end which you might not have seen.

All the best,
Denis

Click to expand...

Interesting that -qh is not documented even by the tool itself, when you use -?.

Have you seen Windows power plan settings explorer utility ? It provides a very nice GUI for power settings.



As a matter of interest, I've been setting 'max power state' to values as low as 30% just to see if my battery life can be extended. I've been forced to run on battery only for a few days, and have been looking for ways to dramatically extend battery life (I know there are many other avenues for this, like screen brightness, shutting down unused apps, etc etc). What is quite interesting is, even at 30%, the 'feel' of the laptop hardly seems any different, while doing a mix of activities like browsing (40+ Edge tabs, 40+ chrome tabs), excel (5 spreadsheets open), outlook (~10 emails open), Foxit PDF, Quicken, Word, etc). Obviously if I were to try transcoding a Video, or play a game, things would be different but for the things I'm doing during the day, it's remarkably responsive still. Whether the battery life is much improved remains to be seen ...

I have not used Windows power plan settings explorer utility but have made a note of its link. Thanks.
I got used to using PowerCfg commands a decade ago with Windows 7. There are only a couple of things I change these days and I change those on-the-fly using a script [as an equivalent of having different power plans, I change specific PowerCfg parameters and, at the same time, change a WMP setting & volume level & a couple of other odds n ends]. The script detects the ComputerName and then behaves slightly differently on my different computers; this allows me to have a single script to maintain that I can just copy across to different computers.
A utility such as the one you suggested might help me during investigations though.

I don't know what sort of battery you have. On my main computer, the battery is an internal one [a design decision that I feel is flawed]. I guess you are in the same position.
- I have 19.5V powerbanks for my main computer and they use up their power before my battery starts getting used. So I use the powerbanks as sacrificial power sources to allow swapping over as they get used up.
- I also have powerbanks for my tablet-with-integrated-keyboard [that just looks like a small laptop]. This computer has an internal battery. It is my 'leisure travel' computer [well, it was until the plague started but it's had hardly any mobile use for the last two years]. It's handy having a computer so light that it & all my other things fit within airline hand baggage limits [generally 10 Kg here, about twenty two lbs] so I can just breeze in & out of airports with nothing to check in & nothing to hang around waiting for afterwards.
With my older computers, that had externally-accessible batteries, I used to buy several then [during day-long journeys] I could just hibernate for a minute to swap batteries over as they got used up. I'd prefer to be able to do that now.
So I have never seriously experimented with changing performance parameters to stretch out battery duration.

I've had several discussions about battery longevity in this forum & in TenForums. My primary concern is always to avoid unnecessarily using up my overall battery life rather than preserving its charge during individual occasions. Because of my use of powerbanks, I have a four year old battery for my main computer that still charges to 100% of its design capacity [because it's hardly ever on its own battery for more than a couple of minutes a day].

My main computer is a Dell. Its powerbanks are made by Dell.
I once tried a third-party powerbank [185Whr] but it was unreliable; it fails completely after a few weeks use. If I leave it for a month or more I can then use it again for another couple of weeks. The supplier tried to be helpful by replacing it but I think they have a design flaw because the replacement behaves in the same way as the original.
I don't know if LG or Samsung make suitable powerbanks for your computers.

All the best,
Denis

Try3 said:

...
I don't know what sort of battery you have. On my main computer, the battery is an internal one [a design decision that I feel is flawed]. I guess you are in the same position.
- I have 19.5V powerbanks for my main computer and they use up their power before my battery starts getting used. So I use the powerbanks as sacrificial power sources to allow swapping over as they get used up.

Click to expand...

This new laptop (LG Gram 17) has a fixed internal battery, as is common these days, but it supports 'USB-C PD', so I finally have a laptop that can be charged with a 'powerbank' as you call it - an external rechargeable battery. I just bought one, and I'm doing exactly what you describe here - I am using the external battery in order to 'save' the internal battery. But I only have one so far, and I'm seeing just how much time I can get from the one battery pack. Between the external and the internal, I'm easily getting 'all day usage', but I would like to see if I can get a full day on the external alone.

By the way - the LG Gram 17 is under 3lbs; it is by far the lightest laptop I've ever held, and it has a massive screen (which I need). Quite an engineering feat. I wouldn't want to abuse it though; I had the Dell XPS 17 briefly before it, and that thing could withstand a nuclear blast! The LG could easily be bent if you weren't careful. But I'd rather have the relative fragility and ultra-light weight!

My main computer is a Dell Inspiron 17-7779, a 17inch laptop with a touchscreen***. It weighs 3Kg [7 lbs].
My abacus is a Chuwi Hi10 Pro with integrated keyboard, in effect a 10inch laptop with a touchscreen. It weighs 1Kg [2+ lbs]. Buying it was an experiment that paid off before the plague when I used to travel a lot. And it fits inside the 'poacher's pocket' of my jacket. It can do everything I want [MSOffice, WMP, browser] but is a bit slow.

*** My first touchscreen computer was a 7inch one over twenty years ago. I decided then that I always wanted touchscreens but it took me until six years ago to get a decent-sized [17"] touchscreen.

Denis