I've noticed that the Windows version of Krita works considerably slower than the Linux one when rendering strokes during drawing. Here's a video I've made to demonstrate the performance difference between Linux and Windows builds of Krita on the same machine: http://youtu.be/aWLhdfBhlbQ You can see that in the first case (on Linux) the strokes get rendered just as I move the mouse cursor and in the second case there is a noticeable lag between the cursor and the rendered stroke. In both cases I use 1600x1200 canvas, 200px brush with Basic_tip_default preset, 8 bit color depth, ~55% zoom level (fit page). Krita version that is shown in the video is 2.8.3 for both Linux and Windows (if I remember correctly) but the development Windows builds don't seem to work any better in that regard. I've tried both 32bit and 64bit versions and haven't spotted any significant difference either. Also turning the OpenGL mode on/off doesn't seem to affect the drawing performance in a noticeable way. I can say that this problem makes Krita almost unusable on my machine under Windows and it seems to be a major issue if we plan to popularize Krita among Windows users. Reproducible: Always Steps to Reproduce: Just try to make some fast strokes with a big default brush Actual Results: There's a lag between the cursor and the rendered stroke Expected Results: The performance that Krita shows on Linux is pretty much the desirable behavior
I'd say this isn't a bug in Krita, but a bug in Windows :-)
Is this with OpenGL enabled on both platforms? Qt's painting code is much slower on Windows than on X11, I'm afraid.
(In reply to Boudewijn Rempt from comment #2) > Is this with OpenGL enabled on both platforms? OpenGL was enabled on both platforms when I was recording the video. But as I said, turning it off doesn't seem to affect the drawing performance.
Hi, Mikhail! Are they running on the same laptop? And what CPU it has?
Boud, do we have Vc enabled on Windows? Probably this might be the reason?
Yes, Vc is enabled on Windows. I can do a double-check, of course.
Oh -- and tbh, on both my laptop (intel gpu) and my desktop (nivida), Krita performs quite okay.
(In reply to Dmitry Kazakov from comment #4) > Hi, Mikhail! > > Are they running on the same laptop? And what CPU it has? It's a desktop though but yes, the same one. The CPU is AMD Athlon 64 X2 5400+.
Check if you don't have smoothing in tool options set to 'weighted smoothing'. I can't quite see it from the video, but I have helped people who were using Krita on windows, whose problem was that that somehow had been on by default!
(In reply to wolthera from comment #9) > Check if you don't have smoothing in tool options set to 'weighted > smoothing'. I can't quite see it from the video, but I have helped people > who were using Krita on windows, whose problem was that that somehow had > been on by default! No, I've made sure that the settings are the same on both platforms, which includes smoothing set to "off".
Hm... I do see a bit of a performance difference, which isn't too strange, since Windows just is slower in pretty much everything, but nothing as huge as on your video. I've tried on five different windows systems, too :-(
Yeah, the situation with my desktop is kinda strange. I've also tried Krita on my laptop (Intel Core i5 4200M, NVidia GeForce 820M) and didn't get that huge difference as well (both with integrated and discrete GPUs if it's important).
Okay -- then I guess there really isn't anything we can do on the krita side... If you're a software developer and have vtune, it might be worth it to run krita in vtune and see what causes the slowdown on the desktop, but that's really deep stuff, since you'd also need to build krita on windows to do that. And that is not a task for the faint-hearted. I think there are four people who have succesfully built Krita on Windows... In any case, I'm closing this bug because we're at the end of our tether here.