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prv8
Fanfold Paper
Posts: 9
Registered: ‎02-19-2019
Location: US
Views: 168
Message 1 of 4

X1 Extreme: Package C State won't go above C3, idle power usage is high

I'm trying to use Throttlestop to improve thermals and battery life. While following this guide:

http://forum.notebookreview.com/threads/guide-improving-battery-life-on-windows-enabling-deeper-c-st...

 

My idle power usage seems to hover between 2W and 5W, but t should be much lower:

 

> Modern mobile CPUs should idle at less than 0.5W, however. (Tested on U, Y, and HQ CPUs) More about C states below.

 

While It seems like the CPU package is never ending a high C-state, but it maxing out at C3. As described in the above guide:

> Over 80% of your package should be in either C6, C7, or C8 state (maybe perhaps even C10!). Is your package idling in C2 or C3? Then you likely have a problem.

 

> All 4-5th generation U, MQ, HQ, CPUs should idle at LESS THAN 1W. 6+th gen U/Y/HQ/HK/H CPUs should idle at less than 0.5W.

 

I've tried quite a few things;

 - Updating all the latest Lenovo drivers + softare (Vantage, etc). Was > 5W during idle, often even > 10W.

 - Removed Lenovo Vantage/other software. This actually seemd to help my idle power usage. Got idle usage to 4-5W.

 - Clean install of Windows and letting it install drivers. Got idle usage of 2W-5W.

 - Disable all the non-core devices to see if it would help unlock package c-states > C3. No luck.

 

It seems like Lenovo is shipping some poor firmware/drivers/software that is limiting the ability of the CPU to throttle down, wasting battery life.

 

 

 

unclewebb9
Blue Screen Again
Posts: 32
Registered: ‎02-20-2017
Location: CA
Views: 123
Message 2 of 4

Re: X1 Extreme: Package C State won't go above C3, idle power usage is high

This is a common problem.  Some laptop manufacturers are deliberately or accidentally disabling the low power package C states like package C8.  ThrottleStop has no problem reporting package C8 if it is actually being used.

 

tazlvt9

 

When you switch to battery power, some laptops will change what C states they use.  Package C8 is not necessary when plugged in but it would help the cause when running on battery power.

 

Some SSD software has a performance option which can disable some of the C states.  This will improve benchmark scores at the expense of battery run time.

 

On my older Lenovo Y510P, I only see Package C2 when I wake my computer up from sleep by using the mouse.  If I use the power button to resume from sleep, I see the full Package C6 which is appropriate for the 4700MQ.

 

Though not C state related, another thing to check when trying to improve battery run time is Nvidia GPU usage.  If ThrottleStop is showing a GPU temperature number, that means some software on your computer is keeping the Nvidia GPU active or Optimus is not supported or not working correctly.  When Optimus is working corrrectly, ThrottleStop should show GPU -- °C on the bottom button where the GPU temperature is reported.  

 

c64ofzZ

 

ThrottleStop is usually not the cause of this problem but if you suspect it is, you can always disable Nvidia GPU monitoring within the ThrottleStop Options window.  On my computer, ThrottleStop never wakes up the Nvidia GPU to monitor its temperature when it is in a low power Optimus state.  Check your computer for any other GPU monitoring software that might be active.  An always active Nvidia GPU can significantly reduce battery run time.

 

zxmar05
Punch Card
Posts: 50
Registered: ‎05-30-2011
Location: DE
Views: 95
Message 3 of 4

Re: X1 Extreme: Package C State won't go above C3, idle power usage is high

The Window Task Manager has a column to show which application is using which GPU (you may have to enable that column to show).

prv8
Fanfold Paper
Posts: 9
Registered: ‎02-19-2019
Location: US
Views: 74
Message 4 of 4

Re: X1 Extreme: Package C State won't go above C3, idle power usage is high

It seems like I'm locked at C3, even on battery. This is after a reboot, and even after a clean install of Windows.

 

I haven't seen any SSD configurations (checked BIOS and installed software) to configure the performance.

 

@unclewebb9 is that screenshot from an X1 Extreme? I'm trying to figure out whether the package C-state being stuck at C3 is an issue with the laptop model, or whether it's something specific to my machine (BIOS config, drivers, etc).

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