5 Replies Latest reply on Apr 8, 2017 10:33 PM by boo radley 2013

    Solution for slow Mixer Brush

    boo radley 2013 Level 3

      hi everyone, I know that for some painters, the lag on the mixer brush when it's set to "sample all layers" is unbearably slow and makes us stay away from that setting (unfortunately). It's such a valuable setting but disappointing that it's useless when turned on. Keeping "sample all layers" turned off keeps the mixer brush fast, but it won't blend with pixels on other layers.


      So after a bit of research, it seems that a few other users have went into the performance settings, and reduced the Cache Tile Size to 128K. I've tried it as well, and miraculously, it seems to have solved the problem. The mixer brush now has no lag when sample all layers is turned on.


      Just thought I'd share this with the other digital painters if it wasn't already discovered. Might come in useful for you guys.


      Question is, what consequences are there when we reduce Cache Tile Size to 128K? For starters, I notice that documents take 10 times longer to save. That's a reasonable trade-off though.

        • 1. Re: Solution for slow Mixer Brush
          JJMack Most Valuable Participant

          It sure would be great it that were true.  I find however its not at least on my workstation.  My workstation Processors are only 2ghz. Mixer brushes seem to be multi-threaded for I see at least half the process are active when I use a mixer brush like the round fan stiff thin bristles.  I see quite a bit activity on 12 processors.. However if I have two layers. My Canon 1D4 16MP image in 16bit color and an empty layer on top. The document is 4886x3264px.  If I use a that brush as  large mixer brush zoomed out so I'm working on all the image pixels.  The lag is painfully slow.  If Photoshop Performance setting are set to 4 cache levels and a tile size of 128k  or 1028k.   If  I zoom in to Actual pixels so I'm only working on a screen size number of pixels the lag is still bad if I use a large tip size like 50 to 60px.  If I use a small tip like 10px there is some lag but not painfully slow. Lag is bad when working on a large number of pixels and become painfully slow as brush size increases. On my windows workstation...


          I think think the only way Photoshop performance could be improved would be to work on the small image being displayed and processing the image actual pixels in the background. Then syncing the the displayed image  with the actual image when the background process become idle. Photoshop was not designed to be a Paint program.  If your a painter an artiest I would think there are better paint programs in the market place then Photoshop.


          • 2. Re: Solution for slow Mixer Brush
            boo radley 2013 Level 3

            at the moment this has really solved my problem and I've been testing it all morning - still no lag, even with larger brush sizes. I'm amazed this actually worked. But I'm still waiting for the consequence.. after all this is Photoshop and you can never have it all with this program. When something seems to have been solved, there's always a catch. But so far so good, I hope this works for other painters as well

            • 3. Re: Solution for slow Mixer Brush
              JJMack Most Valuable Participant

              What size documents are you testing on?  Web size image will not have a problem.   What is the highest resolution camera you own.  Edit one if your image in 16bit color zoom out so the full image is visible on screen and paint with a large tip mixer brush like the round fan stiff bristle brush.

              • 4. Re: Solution for slow Mixer Brush
                boo radley 2013 Level 3

                ..thought I'd update a little progress on the issue. I'm not sure if a slow mixer brush is still an issue with the latest versions of Photoshop, but it still lags on my system even with CC14.2.2.


                Here's a few points which will cause the mixer brush to lag  (on my system, at least):


                -'Sample All Layers' is turned on

                -The document contains visible adjustment layers (Levels, Curves, Hue/Saturation, etc)


                These two points above will always slow down the mixer brush. But I found another solution to get around it, and when I do the following, the mixer brush acts very responsively:


                -When the mixer brush lags, try zooming way out of the document, to something like 6.25%. Then, zoom way back in, to 100% and maybe even closer. Now the lag is gone - and the mixer brush is as fast as the normal brush, even with 'Sample All Layers' turned on and all adjustment layers turned on as well. At this point, you can zoom in/out to any level to keep editing/mixing if you need to, and the brush will still be responsive.


                What slows it down again is turning on/off any of those adjustment layers, or switching to another layer and doing some editing. When returng back to the layer that you're mixing on, it slows right down again. But then zoom way out, then way in, and the lag disappears. At least on my system - I don't know if this is specific to my setup, or why it's happening, but I hope this will also work for others experiencing the same problem.


                -Last, instead of zooming out to 6.25% and then back in, you can try going to "View Print Size" instead, and this also speeds up the brush.

                • 5. Re: Solution for slow Mixer Brush
                  boo radley 2013 Level 3

                  When the mixer brush lags, I zoom way out of the document (to 6.25% or whatever- but make sure you zoom out using "zoom with scrollwheel" - so use the scrollwheel to zoom). Then, click once on the empty canvas area surrounding the document (the empty grey space) and then zoom way back in again - and the lag is gone.


                  I don't know why, but this works on my system. I hope it works for other users as well.