relevant system specs:
windows 7 64bit, intel i7 4790k, 8GB RAM, nvidia GTX 970 [4GB VRAM], wacom intuos 5. all drivers up to date.
running the installed x64 Krita

problems:
the bristle brush is very slow, several seconds behind my actual strokes
other brushes are also sluggish

i would use the bristle brush most of the time.. so this is a problem.
i don't have stabilizer on, and i tried disabling opengl.
i also don't get pressure sensivity on some brushes.

yeah!
i once tried krita on windows 8.1 with a 8800gt and 6gb ram and it was really slow!
strangely enough, everything else ran super fast.
in my experience , it runs the smoothest and best in linux with a plasma desktop,idk if youre willing to give that a try
and i have much much lower specs than your system QwQ

The bristle brush engine is inherently slow, so is the color smudge engine, it's because of the manner they calculate their dabs. For the bristle brush you can try to reduce the amount of hairs the the brush settings.

https://www.reddit.com/r/krita/comments ... ill_krita/

Also check out:
https://docs.krita.org/Instant_Preview

Also, not all brushes have pressure senstivity, because you would not want pressure sensitivity active on all brushes.

that's weird. i don't have a linux machine or a plasma desktop to try, sadly.

i was not quite sure how to reduce the amount of hairs, but i did play around with the settings and reduce things to strip down the brush. instant preview was on, i also tested with it off. i saw some marginal improvements in speed but not enough to be usable.
i guess i should just wait for more updates and optimizations of the brush engine.

i understand about the pressure sensivity is a settings thing then.