The ThrottleStop Guide

Discussion in 'Hardware Components and Aftermarket Upgrades' started by unclewebb, Nov 7, 2010.

  1. unclewebb

    unclewebb ThrottleStop Author

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    @Solf_ - The Power Saver feature was designed for the original Core 2 Duo CPUs which were released about 10 years ago. No further development of ThrottleStop Power Saver ever happened after that because

    a) it is a crappy way to control a CPU and
    b) the modern C States are a much better way to reduce power consumption while maintaining maximum performance.

    Here's a good example. The first picture shows my CPU when it is idle using the Windows Balanced power profile. The multiplier is at its minimum (8) across all threads. This is as good as it gets. Power consumption is measured at the wall for the entire laptop is only 17 Watts.

    [​IMG]

    Next up is the exact same laptop but now it is using the Windows High Performance profile and the reported multiplier is at the max. Full turbo boost in action and much higher VID voltage. Guess what?

    [​IMG]

    Power consumption is identical at 17 Watts. How is that possible? Well, the individual cores are spending 99% of their time in the C7 state where they are disconnected from the voltage rail. Technically speaking, they are running at 0 volts and 0 MHz 99% of the time so in this state, the reported MHz of what the active cores are doing the other 1% of the time really doesn't make any difference. I keep telling people that the easiest way to reduce heat and power consumption and fan noise is to keep a close eye on the ThrottleStop C State data. This is much more important than MHz.

    Next up I adjusted the C7 Interrupt Response Limit (IRL) and this disabled the Package C3 and Package C6 C States. Huge change in MHz makes no difference but without the Package C6 C State, power consumption is way up to 23 Watts at the wall.

    [​IMG]

    The last thing I did was I tweaked the C7 IRL setting and power consumption dropped to only 14 Watts at the wall.

    [​IMG]

    C State residency time is about the same as during my previous 17 Watt screenshot but this little tweak did far more than playing with the MHz. The other interesting thing is the TDP data reports higher power consumption in this last screenshot but actual power consumption from the wall has decreased. That is why I tell people not to trust TDP data when a CPU is lightly loaded. It is just a meaningless number.

    Learn to maximize C State residency time. I let my CPU run at full speed and when idle, the fan is virtually silent and my laptop is cool. The first program I would ditch is Intel XTU. It significantly interferes with the C States. Shame on Intel for not having programmers that are a little more on the ball. :)

    The other thing I forgot to mention is that Set Multiplier does not work correctly if the Non Turbo Ratio is not set to zero. The Power Saver feature uses the same CPU register as the Set Multiplier feature so some of your problems are probably because of this. Next time I look at ThrottleStop, I will see what I can do but it sounds like your script solved your problem. Also, XTU and ThrottleStop are both writing different information to the same CPU registers. That is never a good idea and another reason to ditch XTU, fancy graphs and all.
     
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  2. Papusan

    Papusan JOKEBOOKs Sucks! Dont waste your $$$ on FILTHY

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    XTU is only useful if you want to bench XTU numbers. Then uninstall or disable this huge Bloat/Crapware!! And Unclewebb how it's going with the Papusan version?:D
     
  3. Solf_

    Solf_ Notebook Enthusiast

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    Hi, thanks for replying! Using a kill-a-watt meter is a great idea too -- especially since I have one laying around :)

    I imagine SpeedStep/Power Saver vs C-states depends heavily on what C-states are available. Apparently Dell is known to disable all the more 'advanced' power-saving features.

    So I dug up my kill-a-watt and did some actual testing. I had external monitor connected via HDMI with laptop display off -- hopefully that helps to remove variance due to display illumination and stuff

    The results are:

    Completely idle laptop -- nothing really running except ThrottleStop:
    power saver -- 10.7-10.9W
    full turbo -- 11.1-11.5W
    so about 0.5W difference

    Idle laptop + process explorer (which does tend to reliably require 2-3 percents of CPU time) -- I tend to have it running most of the time, so it's relevant for me:
    power saver -- 10.7-11.5W
    full turbo -- 11.0-12.0W
    so again about 0.5W difference

    Laptop with all the crap I usually have open -- process explorer, Skype, Thunderbird, Firefox (FF is 'idle' -- bunch of tabs is open, but they do not have excessive CPU-consuming javascript) -- basically this is my most realistic 'idle' scenario for the laptop:
    (listed numbers reflect the majority of the time -- sometimes it spikes a few watts when I guess something happens in one of the open apps)
    power saver -- 13.1-14.4W
    full turbo -- 14.7-16.0W
    this is 1.5+W difference

    So, at least 'as configured' on my laptop using Power Saver does, in fact have noticeable effect on the power drain.

    Regarding C-states -- here's what I linked previously with the mostly-idle laptop: https://yadi.sk/i/J98uTzIFt3Fv8

    You mentioned that tuning IRL might help -- I might try that. Looking through the thread though -- it seems like mostly 'try and see what happens' thing? Or is there any method to this?


    "The other thing I forgot to mention is that Set Multiplier does not work correctly if the Non Turbo Ratio is not set to zero. The Power Saver feature uses the same CPU register as the Set Multiplier feature so some of your problems are probably because of this."

    Thing is -- this combination of settings ( https://yadi.sk/i/CqHbAR4vt3FsA ) is about the only thing that appears to 'work' -- i.e. use both 'turbo' and 'speedstep'. Yes, if I set 'non turbo ratio' to zero, I can force-set 32 multiplier. But with 'non turbo ratio' set to default 22 I can use 23 or 24T to effectively request max turbo frequency. And not checking Power Saver is a non-option if I want to try to have speedstep working.


    Anyway, I'll probably try messing with IRL and I'll report the results if I do try it.


    WRT XTU -- I only used it for nice charts to demonstrate how stuff reacts to different ThrottleOptions.
     
  4. illuzn

    illuzn Notebook Consultant

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    @unclewebb Not sure if you saw my earlier message to you - can I have the latest "alpha" version with all C state monitoring enabled. I'd love to test this for you.
     
  5. tilleroftheearth

    tilleroftheearth Wisdom listens quietly...

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    Try sending him a PM instead. :)

     
  6. unclewebb

    unclewebb ThrottleStop Author

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    @illuzn - Thanks for your offer to help. The code I wrote is only in RealTemp so far. If I can ever find someone with a CPU that uses C8 / C9 / C10 then I will add some of this new code to ThrottleStop. Hopefully your laptop uses some of these mysterious C States. Intel adds new features but I am sure that some manufacturers turn them off. My Asus desktop Skylake board has an option for C8 but I don't see it.

    [​IMG]

    @Solf_ I think your Kill-a-Watt has better resolution compared to the one I have. A savings of 1.5 Watts does not sound like much but on a system that is only drawing 15 Watts, I agree that a 10% savings is not that bad at all. Power Saver is not for me but if you are happy with it, I won't argue. :) It's effectiveness really depends on how you have your laptop setup and what apps you have running in the background.

    I saw your C State screenshot before and that is when I noticed that you have a lot of stuff running on your system. It also shows that Package C3 and Package C6 are probably disabled. You would have to contact Dell to ask them about that. A 6th Gen Skylake would be using a lot less power at idle if all of the package C States were enabled. Did you ever check this when you had Windows 10 installed?

    @Papusan - Sorry Pap. Summer arrived. My wife is a school teacher. I never get anything done during the summer. :)
     
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  7. Bug in

    Bug in Notebook Enthusiast

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    Hey!

    I'm using XTU and not very satisfied for the moment...
    Is throttlestop optimized for skylake? I heard the version 8.2 will be good, any dte of release?

    Thanks a lot!
     
  8. tilleroftheearth

    tilleroftheearth Wisdom listens quietly...

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    Bug in, see the last sentence in the post above yours. ;)
     
  9. DackEW

    DackEW Notebook Consultant

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    I think for Skylake CPUs these switchers turn on / off differet things than for earlier CPUs. Like this Power saver is the new Speed step switch or the BD Prochot the 800MHz mod.
     
  10. Bug in

    Bug in Notebook Enthusiast

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    M bad, didn t read it to the end... Guess i'll have to wait then!
    Thanks!
     
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