Hi all,

first of all, thanks to the developers for such an amazing and feature-rich piece of software. I have to admit, I did need some time to get used to the workflow, but after a few weeks of working with it, I have now come to appreciate the power that comes with the different layer types, transparency masks, alpha inheritance and so on. Please keep up the good work.

That said, I still experience Krita to be almost unbearably slow with some operations that I need almost on a daily basis. It's about five years now that I described a similar phenomenon in this thread and I would love to say the situation has changed. Alas, it hasn't. To better demonstrate, what I'm talking about, I recorded a quick screencast:

https://youtu.be/r2WaEMa-npY

As you can see...

• converting a typical image from RGB to CMYK takes about 13 seconds
• opening the channels dockers takes about 2 seconds
• hiding or unhiding one of the channels takes about 5-8 seconds
• when adding a filter layer, the dialog box takes over 2 seconds to even appear
• when clicking one of the filters - say, Slope, Offset, Power - I can watch the screen preview to appear tile by tile, which takes about 16 seconds

I really don't want to sound overly demanding, but to me this borders on the software being almost unusable. Note that my machine is running Linux (Mint) has 64GB of RAM, 32 of which I have dedicated to Krita. Also, I'm using an NVIDIA GTX 1080 with the latest drivers.

Is anybody else experiencing this? Is this normal behavior? Any ideas, what I could try?

Any help would be much appeciated.

Check if turning off your window manager's compositor makes a difference? Because my machine is way more terrible than yours, and it doesn't even begin to have anywhere near those times. (Like, undo history COULD have a build in delay to ensure Krita spends most of it's time on actually processing your actions instead of putting data in the undo history, but that doesn't explain the channels docker).

EDIT: no, sorry, please report a bug for the channels docker being this extremely slow at bugs.kde.org under the product Krita. I can reproduce it with Tyson's full size image for our splash screen. It completely freezes up Krita.

The rectangles on the filter layer are... there's not much we can do there. Those rectangles are the multithreading in action, and while we're always trying to improve the speed of krita, you will always end up seeing the rectangle-updates at huge sizes. The only other option is not to give any feedback whatsoever during this time, or to do the filter on a small version of the image while in feedback mode, though this might result in precision issues and eventually Krita is going to have to calculate the precise version, so this will just... delay the lag.