[Guide] Improving Battery Life on Windows [+Enabling Deeper C States]

Discussion in 'Windows OS and Software' started by Che0063, Apr 14, 2018.

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What was your increase in battery life after following this guide?

  1. None (decreased)

    20.0%
  2. 20%

    16.0%
  3. 40%

    28.0%
  4. 50% +

    36.0%
  1. respecz10378

    respecz10378 Newbie

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    Thanks for this post

    My laptop first idled 15-20W, and now is consistently 3-4W. It also can reach C8 state, where beforehand it couldn't get any further than C3.
    Battery life increased from 3 hrs to 8+ hrs.
    Unfortunately, updating the drivers didn't seem to work. So I just used the built in windows reset option, and this fixed the issue somehow.
    I think a windows update caused it to get stuck in C3.
     
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  2. Che0063

    Che0063 Notebook Evangelist

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    New discoveries - some poorly-optimized drivers can be the cause of even more battery woes. I thought I got my package C states down well, but apparently not. My Goodix Fingerprint driver, as well as the Axes Accelerometer caused C0% to be 0.5% higher, and causing a system-wide 0.2-0.5W increase in idle power.

    C state heaven: C state 2.jpg
     
  3. Maleko48

    Maleko48 Notebook Evangelist

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    Did you disable/remove them or just update the drivers?
     
  4. Che0063

    Che0063 Notebook Evangelist

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    Just disabled. There are no available driver updates. My theory si that, by disabling the drivers, the CPU is no longer trying to communicate with the device and wasting CPU cycles.
     
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  5. Simon787

    Simon787 Newbie

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    Thanks for the Guide!

    I have an Ideapad 330S and I've been struggling with getting good C-states on it. I got it into C3 which is 0.2W lower than stock C2 but it still draws 1 Watt at idle. It does go into C8 no problem (0.3 W) after disabling the Wifi adapter in device manager. This Laptop came with a Qualcomm QCA9377 which I have since replaced with an Intel AX200 but that didn't fix the problem.

    Please help me... I tried everything from updating drivers to fiddling with services.
     
  6. mergen3107

    mergen3107 Guest

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    Thank you for the detailed guide!

    My laptop (see my signature for specs), now idles at 0.8-1.5 W, both on battery and AC power, with no programs open (it gets to 3-5W if I open Firefox with 2 windows and ~20 tabs).

    I have a Lenovo USB-C Hub with LAN, a few more USB ports, and an SD card slot. Without it I can see my CPU entering C8 state, but with the Hub connected, I only have C2 and C3 deep states.

    Recently I updated Intel RST driver directly from the Intel website. Now I think I shouldn't have done it :D
    Lenovo-provided IRST driver is older than that one, so now I can't change the driver. So probably I should wait until Lenovo issues a newer driver.

    P.S. I forgot to mention that MSI Afterburner takes extra 4-5 W in idling! For battery only use I just disable it. Otherwise, battery drains in 3-4 hours, instead of usual 7-8. I didn't notice after which MSI AB update this started.
     
    Last edited by a moderator: Sep 17, 2019
  7. Che0063

    Che0063 Notebook Evangelist

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    Welcome to NBR. If two separate WiFi cards both exhibit the same issue, I can only imagine that the issue lies somewhere within your M.2 (?) to CPU interface. The AX200 is connected over PCIe 3.0 x1 for WiFi and USB 2.0 for Bluetooth. QCA9377 is connected over I²S, PCIe 2.1, PCM, or UART, for Wifi depending on your configuration. It can be hard to tell. As a previous owner of the (crappy) QCA9377, I can say that I haven't had problems with it.

    I'd suggest updating your Serial IO, M.2, PCIe, or any interface drivers.
    upload_2019-9-19_6-55-56.png
    I'm happy to have helped.

    Unless you are about to die from missing out on a special Lenovo feature, there is no need to stay with Lenovo drivers if Intel's drivers are working fine.

    MSI Afterburner is likely keeping your GTX 1050 "on". I'm guessing that the software is keeping the GPU on but putting no load on it. When you aren't playing games, Nvidia Optimus (theoretically) disconnects power to the entire GPU, thus saving power.

    Over/under-clock/volt settings should remain closing MSI Afterburner.
     

    Attached Files:

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  8. mergen3107

    mergen3107 Guest

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    Yeah, I am more a conservative 'don't touch it if it works' guy :D

    This is a known issue, as I found, of MSI Afterburner conflicting with NVidia Optimus. Devs say AB is not supposed to work with laptops. Looks like they changed some mechanisms of polling the GPU, so AB requires now more power even though it says the dGPU is idling.


    That's a very good news! However, MSI AB seems resetting to previous profile whenever I restart it. GPU-Z confirms that, showing frequencies of previous profile after I close AB and run a game. Weird!


    ---

    Another thing I remembered about power saving, you probably would like to add this to your guide: powercfg

    This is a built-in Windows command-line tools that allows you to do many things. Personally, I use 'powercfg /energy' command to generate a report that states all different power issues, including those related to CPU, detailing which processes are power hungry.
    Also I used 'powercfg /requests' to find and disable all USB-powered requests coming from connected devices. I disabled the mouse requests so it didn't wake up the laptop during sleep (that case was with my old laptop which wasn't supposed to have Windows 10 installed :D So its CPU didn't properly support selective USB suspend option).
    But still this is a very useful tool to trace down any power hungry peripherals.
    An example of commands and their description you can find, for example, here.
     
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  9. mergen3107

    mergen3107 Guest

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    One more investigation result.
    On my laptop (Lenovo 720S-15IKB) I have two USB-C ports. One is USB 3.0, another is USB 3.1 (Thunderbolt).
    Without anything connected, I have 0.8 W, C8 deep state active.

    So, if I connect my USB-C Hub to Thunderbolt, CPU power goes from 0.8 W to 1.8-2.0 W stable, no C8 deep state.
    However if I connect it to USB 3.0, the power raises to only 0.9-1.0 W, but no C8 deep state active.

    Looks like this is a common 'feature' of Thunderbolt to drain more power.

    I am puzzled though, why connecting the hub causes deep states to go away.
    So in this hub there are 2 USB 3.1 Type A ports, 1 full SD card slot, 1 HDMI port, 1 USB 3.0 (?) power-delivery port, and an RJ-45 port.
    Probably, it is because of the power-delivery port. Or due to HDMI (which should start communicating with the iGPU, right?)
     
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  10. Che0063

    Che0063 Notebook Evangelist

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    You're not alone. It puzzles me too. Any device I plug in anywhere causes the C states to go ever so slightly higher - that includes the most basic mouse/keyboard.

    Still at a loss as to why my m3-7Y30 idles at 0.4W, whereas my friend's m3-5Y10c from two generations ago idles at 0.2W.
     

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