Screen Flickering - Help :)

Discussion in 'Windows Virtual Machine' started by ChrisP7, Jan 3, 2017.

  1. Did you have this issue before? Or maybe with specific apps?
     
  2. BrianL7

    BrianL7 Bit poster

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    So I've changed some settings and thus far have not encountered further screen flickering! It's worked on my new 15" MBP w/ TB and my 27" iMac w/ 27" Thunderbolt Display. :)
    15" MBP w/ TB (w/ 16GB RAM)
    A. Parallels Hardware Tab:
    1. CPU & Memory: Set RAM to 6000 MB (6 GB to prevent memory swapping; it leaves MacOS with 10GB).
    2. Graphics:
      1. Set memory to 1000 MB
      2. Resolution: Check the "Scaled" box
    B. Parallels Options Tab:
    1. Full Screen: "Scale to Fit Screen" = Off
    C. In the running Guest OS (Windows 10, etc.), apply these settings:
    1. Set screen resolution to "1680 x 1050 (Recommended)"
    2. Advanced Text Sizing (Scaling) set to 100% (or scaling off)
    27" iMac
    All the same steps above, but in Guest OS (Windows 10), Set screen resolution to "2560 x 1440 (Recommended)"

    I can't say that this is the best or most preferred solution, but it seems to have solved screen flickering while leaving things at resolutions I can work with. Good luck!
     
    Last edited: Mar 1, 2017
  3. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

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    3,158
    Thanks for the suggestion, BrianL7, we will test it in our lab with the same environment and let you know the results.
     
  4. CesarPedro

    CesarPedro Bit poster

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    I have similar problem, but my flickering is in magenta colours. Its really unusable in full screen mode.
     
  5. CesarPedro

    CesarPedro Bit poster

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    I have solved the problem uninstalling Parallels from OSX, downloading the last version and reinstalling it.
     
  6. SvenO

    SvenO Bit poster

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    I have got a Retina Mid 2014 with
    NVIDIA GeForce GT 750M 2 GB
    Intel Iris Pro 1536 MB
    Graphics

    since i have upgraded to V13 i also have got this awful screen flickerings ... i cannot exatcly say what the reason for this is. When i start Windows 10, evreything is okay. I am using 2 monitors with an adapter which is connected to the thunderbolt port. Maybe its the number of open applications and windows. Then it starts flickering (after 10 minutes up to 2 hours) and gets then worse very fast. Very bad when you try to move any windows or open/close apps. It leads very far to the situation that screen content is totally unreadable and that its only luck that you are able to identify the restart button on the screen. I also have this new effect that i first have a pink screen when i wake up my macbook. I really hope that the parallels team will find a solution for this. Up to now i had three times the situation that it was very hard to save my work before restarting, because screen content was not redable anymore ....

    best regards
    Sven
     
  7. Arun@Parallels

    Arun@Parallels Parallels Support

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    1,356
    Hi @CesarPedro , we are glad that your issue is resolved. Please reach us anytime for further assistance.
     
  8. Arun@Parallels

    Arun@Parallels Parallels Support

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    Hi @SvenO , please try to update to the latest build of Parallels Desktop 13 for Mac and check if that helps.
     
  9. ChristopherG1

    ChristopherG1 Bit poster

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    I have the same exact issue since I upgraded to Parallels 13. I have sent a few videos to support, but have not received one reply. Happens at least a few times everyday. Suspending and resuming fixes the issues for a short period of time, but it always comes back.
     
  10. RamonS1

    RamonS1 Bit poster

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    Exactly the same problem since I upgraded to Parallels 13 . I check my version in order to install the latest one but it is suppose to be the last one (
    Versión 13.2.0 (43213)).

    Please help! any idea

    Ramón
     
  11. jeremyw1

    jeremyw1 Bit poster

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    I have the same issue with PD13. None of the fixes here helped. Falling back to PD12 didn't help. Interestingly some Win10 VMs work great. Others won't stop flickering. Upgrading to PD13 was a really bad idea.
     
  12. Arun@Parallels

    Arun@Parallels Parallels Support

    Messages:
    1,356
    Hi @jeremyw1 , please uninstall Parallels Desktop 12 for Mac and reinstall Parallels Desktop 13 for Mac latest built now and check if that works.
     
  13. jeremyw1

    jeremyw1 Bit poster

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    Is this Version 13.2.0 (43213) the latest?
     
  14. MikhailI1

    MikhailI1 Bit poster

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    I've just managed to avoid a heavily blinking issue.
    Problems began when I connected the second monitor. I've increased the amount of the virtual video memory as Parallels asked to 512M, but the performance was very bad anyway, so I've disconnected the second monitor. Parallels became unusable at this point: heavy blinking after logon. Steps taken to restore the functionality:

    1. Increase video memory to 1M, virtual memory to 8G, acceleration off.
    2. Blinking stopped, but VM was unusable: very slow.
    3. It appeared that screen resolution in Windows was set to double on both dimensions (and the text size increased too, so the change was not obvious). That means that the screen size was 4 x normal: 5120 x 2880 instead of real 2560 x 1440.
    4. Screen size in Windows restored to 2560 x 1440, text size changed to minimal.
    5. No blinking, speed Ok.

    Looks like adding the second monitor renders Parallels inoperable. Hope this helps.
     
  15. jayan

    jayan Bit poster

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    The main cause of screen flickering is related to display driver so ensure that it is up-to-date. More over uninstall the driver from device manager and reboot your system. The second cause is a third party application. To check whether it is affecting the scenario.

    Screen Flickering Windows 10 Laptop Endlessly How to Fix
     
  16. AthosF1

    AthosF1 Bit poster

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    I solved the problem of flickering with win10 on my 27-inch iMac using the virtual machine after selecting the "resized" function in the "graphics card" menu, losing the high-resolution graphics .. I have tried everything, but this is unique way to give resolution to flickering ..
     

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