Windows 10 and Hyper-V dynamic memory Solved


  1. Posts : 52
    Windows 10 Pro x64 version 1703
       24 Jan 2016 #1

    Windows 10 and Hyper-V dynamic memory


    It seems that Windows 10 does not behave nicely in a Hyper-V virtual machine, also running on Windows 10.

    My laptop has plenty of memory and is running Windows 10 build 10586.63.

    Normally I configure a new VM with dynamic memory enabled, because I saw no reason why not. Now I found one: Windows 10 as client OS does not like that. All my Windows 10 VM's reported only about 1.5 GB usable with 4 GB configured. Not surprisingly, they were all dead slow.

    When I disabled dynamic memory in the settings, the problem went away.

    This may severely limit the number of VM's you can be running simultanously!

    Bart
      My ComputerSystem Spec

  2. Kari's Avatar
    Posts : 15,138
    Windows 10 Pro
       24 Jan 2016 #2

    Of course a Hyper-V vm becomes slower if you use dynamic memory with default settings. The Hyper-V will be constantly monitoring the demand and assign the required RAM to the vm.

    For the dynamic memory to work you need to assign enough startup memory (#1 in screenshot below), increase the the memory buffer (#2) and memory weight (#3):

    Click image for larger version. 

Name:	2016_01_24_16_58_091.png 
Views:	6 
Size:	124.1 KB 
ID:	60455

    A Windows 10 virtual machine needs surprisingly little RAM to function well. Here in the screenshot the memory usage of a Windows 10 vm otherwise idle at the moment, only running Macrium to create a system image. Memory demand only 522 MB but because I have assigned a 35% buffer, it's using 768 MB of the assigned maximum 8 GB:

    Click image for larger version. 

Name:	2016_01_24_17_03_572.png 
Views:	3 
Size:	102.1 KB 
ID:	60458

    The buffer is important: When using dynamic memory and the demand suddenly increases for example due a resource heavy application being launched, it takes time for Hyper-V to assign more RAM to the vm. The bigger the buffer, the better the vm reacts to increased demand.

    Dynamic memory should only be used when it really is needed, for instance when it is important to have multiple virtual machines running at the same time. Dynamic memory should not be used when installing Windows, it can make the time needed for installation somewhat longer.

    Generally speaking a Windows 10 vm with 2 GB of static RAM assigned works faster than the same vm with 512 MB to 4 GB dynamic RAM.

    Kari
      My ComputerSystem Spec


  3. Posts : 52
    Windows 10 Pro x64 version 1703
    Thread Starter
       24 Jan 2016 #3

    Thank you for your excellent explanation!

    I will keep this in mind, but generally will follow your advice to not use dynamic memory unless I really need it.

    Regards,

    Bart
      My ComputerSystem Spec

  4. Kari's Avatar
    Posts : 15,138
    Windows 10 Pro
       24 Jan 2016 #4

    You are welcome :)
      My ComputerSystem Spec


 

Related Threads
I am using Windows 10 Insider Preview 11082 (upgraded from Windows 1151 fully updated. I had installed the Hyper-V feature in the latest Windows 1151 but had not used it before I received and installer the Insider Preview edition. The...
Hello, I'm running a 64 bit Windows 10 laptop. On idle, the System process is showing a high memory usage of more than 150 MB, usually more than 200 MB. Using poolmon the pooltag SpDN showed up with a memory leak. It leads to the Intel Matrix...
I love the Windows Spotlight dynamic wallpapers on the Windows lock screen. I would love to have the same feature for the desktop as well. I know I can collect pictures in a folder at set a background slideshow but I am too lazy for that I just want...
Hi there Even if you are using a 64 Bit OS don't over commit RAM when the VM starts - HYPER-V allows you to set DYNAMIC RAM which means the OS will grab more when it needs it - and then of course you can run MORE VM's or have a better throughput...
Our Sites
Site Links
About Us
Windows 10 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 10" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd
All times are GMT -5. The time now is 21:47.
Find Us