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Slow mask brush ON1 Photo Raw 2023 M1 Mac



  • Brian Lawson Community moderator

    There can be multiple causes for the brushing lag. They all come from the fact that the brush movement is tracked by the GPU which is simultaneously re-rendering your image as you are brushing. This is what the Video Card Strength slider is for in Preferences > System > Performance. Moving the slider right tells the program to spend more GPU time on rendering so you can move it left to get better brush tracking performance.

    Turning on Fast Preview will also improve brush tracking as it tells the program to do less rendering while brushing. You'll see a lower res version of the image while brushing.

    The Performance settings are covered on page 265 of the User Guide.

    The Editing Pipeline (pg 74) also has an affect on brushing. When you are working on a mask that is at the beginning of the pipeline (lower in the editing stack) everything that comes after that point has to be re-rendered. The more stuff there is in the pipeline the longer it will take to do the rendering and the more stuttering you'll see. This is especially true when processor intensive features are used like Blending Modes and Effects like Dynamic Contrast. Temporarily turning off Effects above where you're working can help improve brushing performance.

  • Barb Harvill


    Thank you for the tip to turning off Effects above where I was working.  Worked like a charm. 

    I was doing a local adjustment and the masking was so slow I couldn't even move the brush after pressing left mouse button. Took minutes to return screen.  Same with pressing view for mask or changing view zoom.   I turned off all effects (no local adjustment was above the one I was working on) and it was magic.

    FYI My system:

    Intel I9-9000 3.10GHz

    32 GB ram

    current windows 10 version 22H2

    All drivers updated including latest Video card NVIDIA driver

    Moved Scratch folder to external SSD drive

    Have changed system preferences to video card strength to high and checked GPU render and fast preview


  • Marcel Bahnen

    An update on this matter, using the lastest version of on1 Photo Raw 2024.

    At times the mask brush becomes so slow that it cant be used: brushing is impossible. 
    Specs havent changed. I started to do the usual things like turning of all effect layers etc. When i fired up the Activity Monitor i saw something interesting: as soon as i start brushing the CPU% shoots up to 130-250% but the GPU never goes higher then 30-50% even though I i set to 80% and performance to GPU.
    I use a Wacom Intuos, by the way, with the latest driver. 
    The problem is that I want to fine tune a sky replace mask but its impossible due to this lag.  The only solution seems post correction inPhotoshop but that is somewhat silly.  Any ideas, anyone?

  • Brian Lawson Community moderator

    How is your Wacom Tablet connected to your computer? I just replaced an ancient and no longer supported but still functional Intuos 3 with an Intous Pro Medium. One thing I noticed in the installation docs was their recommendation that the tablet be connected directly to the computer for best performance. I have mine connected through a Thunderbolt 3 dock but it isn't daisy chained to another devices or hubs.

    Can you post the image file you were working on so I can try it on my system and see if I have the same performance issues with it? That will give us a better idea of whether to focus on your system or your editing for the cause. Zip it together with the .on1 sidecar so I have all your edits too and upload that to a file sharing service like Dropbox or WeTransfer then post the download link here and I'll take a look at it.


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