Unscaled App Windows Flickering on 4K TV w/Windows 10 Scaled to 225%

  • Hello, I've noticed an issue with programs' windows flickering on Windows 10 when i have the display scaled up to 225% (4k 65 inch TV).

    Some applications, most noticeable to me is the battle.net app is blurry when the scaling is set as such, and flickers whenever flux is enabled. Reducing the scaling back to the original 100% (impossible to read text) or disabling flux (ow my eyes) resolves the issues. Other unscaled applications seem to have the same issue when their is redraw within the app.


  • Hi Flux creators,
    It's very nice of you to make and maintain this software. Especially for free.

    It works well on my AOC E2752Vh 27" 1920x1080 monitor and ATI Radeon HD 4850 graphics card. I read another post about a flicker during transition. When I turn on the computer in the evening, the transition is noticeable but it's brief and understandable.

    Why I'm writing, especially as a reply to this post, is I'm testing out 4K Hisense 50H6C TV, as a monitor, to upgrade. I got a 4K capable card, albeit not a gaming card, PNY Geforce 710 1GB. When I first turned on the monitor, there was a horrible flicker. After some fiddling it turned out to be Flux. So I disabled it.

    After some more fiddling to increase the Chroma, I found "Game Mode" on this 4K tv. So I enabled that. The whole tv goes black for a second then on again, very bright. This indicates that the tv uses different hardware (and software) in Game Mode.

    To my pleasant surprise, Game Mode creates much sharper text and is much more useful as a monitor. But it's really bright.

    Xorag, see if your tv has Game Mode. I'm using the 4K tv right now to write this message with no scaling on Win10 and can see the text very clearly. Before Game Mode, the text was slightly blurry at no scaling. So I adjusted the sharpness and brightness and color. You should try adjusting those.

    What I learned so far is Chroma not at 4:4:4 is what makes the fuzziness. TV and Monitors that have Chroma 4:4:4 will not fuzz. Below is a test image I found to see if you have Chroma 4:4:4 ...
    Be sure the image is at 100% not scaled up or down to prevent scaling fuzziness.
    If you can clearly read the bottom two lines of text with the Red and Blue backgrounds then you have 4:4:4.

    Before Game Mode, I couldn't read them. In Game Mode it's mostly readable. Not as great as my 'dedicated' monitor but good enough for the price and size of 4k tv. I paid $400 for this tv while 4k monitors are currently much higher.

    The other thing Game Mode seems to have fixed is lag.

    As for Flux, it did get better with Game Mode on my 4k tv but programs still flicker when I reduce down to halogen or lower. When i have flux at sunlight the flickering is very slight but still noticeable when programs are moved, or they refresh etc.

    I want to report to the Flux team that the flicker is on even Win10 basic fundamental programs like Task Manager and Windows Explorer. No flicker on Firefox.

    I'm still experimenting but did want to put my current findings out there in case others are also experimenting. If so, we can share notes.

  • Hi,
    This is an update on my previous post.

    I purchased an XFX Radeon RX 470 4GB graphics Card and a Samsung 4K 40" TV UN40KU6300FXZA.

    Flux doesn't flicker the screen (especially Windows Explorer nor Task Manager) at all with this combination. Even if I scale to 225% or 300%. Even in all TV modes (game seems best as a computer monitor).

    So it must be either the graphics card, driver, or monitor problem.

    Hopefully this helps someone.


  • hi everyone, since posting the original issue, it has not seemed to recur. cannot be sure why but once i sorted out my game mode and proper resolution/color output on the 4k TV, this issue has not returned.

  • I've got this problem with a GTX 1080 and Samsung UN49KS8000 TV. I'm glad this game up as top result in a Google search for "4k makes windows flicker," was making me concerned because I couldn't identify any source for the flickering. Luckily it's only noticeable in random windows that I don't have any consistent need for (Task Manager, nVidia Control Panel). Just adding in case someone else goes searching any of those terms and is worried. Also looks like restarting Flux might fix it.

  • Just to circle back on this issue, I have not experienced the issue in quite some time. I'm not sure if this was related to an Nvidia driver update, a flux update, or a windows update but it just went away and never came back. Thanks.

  • [link text](link url)https://www.youtube.com/watch?v=vHowP9gUsUE&feature=youtu.be&a=[link text](link url)

    I fix the screen issue if anybody wants to know here is how to fix it..

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