Does RAM affect laptop battery life?

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Drew1, Sep 22, 2019.

  1. Drew1

    Drew1 Notebook Deity

    Reputations:
    13
    Messages:
    1,548
    Likes Received:
    41
    Trophy Points:
    66
  2. bennyg

    bennyg Notebook Virtuoso

    Reputations:
    1,552
    Messages:
    2,347
    Likes Received:
    2,344
    Trophy Points:
    181
    Ignore, that is anachronistic puffery. They list *platform* benefits of DDR4 vs DDR3. (Which is rather pointless since you don't have DDR3 in your laptop to see that benefit)

    The effect on runtimes mainly depends on whether you currently have 1x8gb or 2x4gb.

    Replacing 4gb with 8gb sodimms will add very little to power consumption.

    Adding a ram stick will use an extra Watt or so up to maybe 5W under stress, but will also give the performance benefit of dual channel.

    Depending on your system, programs and usage, the extra memory could improve runtime by keeping shuffling data around to fit in limited ram to a minimum (OS juggling using cpu, fetching from storage, which use power)
     
  3. tilleroftheearth

    tilleroftheearth Wisdom listens quietly...

    Reputations:
    4,867
    Messages:
    12,293
    Likes Received:
    2,311
    Trophy Points:
    631
    That 40% reduction in power needs to be tied into a single and specific workload and specific component(s), which it isn't. ;)

    Note also that it doesn't say the battery life will be extended by the same %age either...

    More RAM will always do more work. Whether or not double the RAM will give you more run time depends on many factors, including your workload/workflow and how your O/S was set up too.

    For example, compared to 4GB and 8GB configurations for an ultrabook, 16GB and 32GB RAM options may give the same battery run times, but greater amount of work performed and/or a smoother running and much more responsive platform (on latest-gen Intel processors) when the workload is light/lighter.

    For heavier workloads, more RAM allows other components to be taxed more fully ( CPU and storage subsystem) which may result in less battery run times (in an absolute sense), but still, should have a positive increase in total work done vs. the lesser RAM equipped options.

    With 16GB/32GB or more, (and depending on the specific programs you are running), disable the pagefile, the hibernation file and System Restore to get the most use of that RAM by bypassing the storage subsystem as much as possible. Bypassing the storage also offsets any increased power usage the greater RAM may need. ;)

    Combining a maxed out RAM platform with the most battery efficient storage subsystem (Intel's 660p M.2 PCIe drives 1TB or 2TB models only, OP'd by 33% or more) will give you the best combination of long battery life and a very responsive system too (just make sure you are not doing video editing or any other storage subsystem intensive work on this NVMe drive though).

    Which notebook do you have? What is the battery life now? What are your current or intended future workloads/workflows for this system?

    (I am guessing that this is an ultrabook class notebook that is not used for very heavy digital processing).
     
  4. ole!!!

    ole!!! Notebook Prophet

    Reputations:
    2,271
    Messages:
    5,745
    Likes Received:
    3,667
    Trophy Points:
    431
  5. pete962

    pete962 Notebook Evangelist

    Reputations:
    117
    Messages:
    474
    Likes Received:
    215
    Trophy Points:
    56
    I guess "reduced power consumption by up to 40%" comes from shutting down HDD or SSD, which normally would need to be run for swap file access. with more RAM no need to swap data to storage and it could go to sleep. If you assume typical HDD can use up to 5W and you shut it down on some ultra efficient laptop, you could get up to 40% reduction in power usage, maybe in some specific scenarios, especially if you upgraded from let's say 4GB, where data swapping would be almost constant. And the key word here is "up to", in reality it means "much less than", LOL.
     
  6. ha1o2surfer

    ha1o2surfer Notebook Evangelist

    Reputations:
    71
    Messages:
    518
    Likes Received:
    106
    Trophy Points:
    56
    I will just put these numbers here for you.

    HP CF0012DX, 4417U Single 4GB ram stick - idles around 2.062w - 2.101w
    HP CF0012DX 4417U Dual 32GB sticks 64GB total - Idles around 2.167w-2.212w

    so.. under idle conditions it doesn't add much at all. Under load i didn't test but I can i guess..
     
    tilleroftheearth likes this.
Loading...

Share This Page