I'm using Krita 4.0.0 on a Surface Book, Win 10 Pro, i7-8650 CPU with 16GB RAM. I have a small and simple image, but Krita is hanging for minutes at a time and (apparently) reporting using over 9GB of RAM. I've found posts about similar problems on various forums (some dating back about 4 years), but haven't been able to find a fix.

By "small and simple" I mean 1000 x 1000, with three layers (a mid-grey canvas, a painting layer, and a layer of rectangular frames) and all painting done in greyscale (sRGB colourspace) with the default "Bristles 2 - Flat Rough" brush (enlarged to 200px). The title bar is telling me it's using 4.8GB, but the status bar is reporting 9.3. Before my last brush stroke, both were reporting 4.8 (which still seems high), but then with one stroke Krita hangs for a few minutes and the number in the status bar almost doubles and tells me that swapping has been started. (I'm not going to pretend I know what those numbers mean -- Task Manager is telling me less than 1GB throughout).

I've left all the settings at their default values except Internal Pool -> 35MiB and File Size Limit -> 8GiB. Memory Limit is 8154MiB. Shouldn't this be enough?

I'm hopeful that I've just made some trivial mistake in setting up my image. Any pointers would be gratefully received.

Please make the .kra file available so we can check what's up.

The .kra is here:

https://www.dropbox.com/s/ja1ulwji3pbyluh/Thumbnails%2001.kra~?dl=0

Thanks for your time.

Meh... My answer somehow got eaten by the forum. In any case, the problem is with the Thumbnails layer. Even though checking the bounds doesn't show anything weird, it's way bigger, even in the file, than it should be. Doing a trim to image size trims it down and makes the file take a normal 16mb. I'm not sure yet what made this happen, but at least, if you do that, you should be able to continue working. I'm still trying to figure out what is in that layer that is invisible, doesn't show up in the layer bounds but still takes a lot of memory.

Yeah, my first attempt at the question got eaten too

But that's awesome. Totally works.

Could it have something to do with the template I created the image from? I made the template on day one after installing Krita (to make sure that I could never escape my initial cluelessness, apparently), and it turns out that the image starts off at 18.1M. Trimming the "Thumbnails" layer to image size brings it down to 12.5M, so there's clearly something wrong right from the start. It also turns out that the initial "Canvas" layer is the wrong size, too.

I'd be very interested in any other details you can dig up, but that's a totally acceptable answer. So thanks very much for taking the time.

Could you also share the template so I can have a look? Thanks!

Damn, I fixed the template after reading your post. Should have made a copy . I'll have a go recreating the problem, but I suspect I just got "lucky" last time.

Cheers