Hi there. I just updated to 2.9 on the Krita Lime PPA, I am using 2.9.8 stable.

I've been testing it out (huge improvement over 2.8 in almost every area, holy cow). I've noticed that when painting with large brushes on anything other than 8-bit color depth, it is incredibly laggy. Example: 2048x2048 image, Airbrush_pressure @ 400px.. it's very laggy at 32bit color depth but pretty smooth at 8bit. Same lag with 16bit and 16bit Float.

I have GPU acceleration on (GTX 780, proprietary drivers). I have also tinkered with the texture buffer and scaling mode settings which had no effect. Some brushes like Block_bristles @ 400px can take up to 20 seconds to draw a single stroke. I realize some brushes might be a little more taxing than others, but this seems a bit excessive. Is this normal?

I also get some blocky artifacting when drawing with large brushes: http://i.imgur.com/2Kzfx3C.png

I am on Mint 17.2 KDE

Thanks

It depends a lot on your hardware: your cpu, available memory, cache, driver, opengl other things that are running, so yes, this could be perfectly normal. A 32 bits/channel image is _big_. It takes 4 bytes per channel, 32 bytes per pixel. With some graphics cards/driver combinations 16 bit/floating point actually is sort of a sweet spot since the gpu needs to do less conversion from image data (which is stored in cpu memory) to display data (stored in gpu memory), for others the conversions is a nearly unsurmountable step.

If a really small image, like 2048x2048 and a 400px brush gives trouble, it's probably at least partly your system. However, you can always play with the spacing parameter of the brush: those are optimized for quality and 8 bit images. Make the spacing wider, and the brush will be more responsive.