I’m making this post sticky. Hoping that someone can pass this to the developers. It’s also here for those that are on macOS and are considering of using Krita for big projects. The primary system I do all my studies on is a “MacBook Pro” that I got secondhand:
Processor: 2.8 GHz Intel Core i7
Memory: 16 GB 2133 MHz LPDDR3
Graphics: Intel HD Graphics 630 1536MB
With “AMD Radeon Pro 560” built-in.
Currently running macOS 10.14.5. This is a good spec for 2D works, but Krita doesn’t do that well on macOS, unfortunately. I’m currently testing out 20,000 x 20,000 px @ 300dpi. Here are a few anomalies:
1) When “Canvas Graphics Acceleration” is checked:
Brush stroke (using the “Basic-5 Size” brush) is normal at 100% zoom. At 50% zoom level, it’s still doing good. 45% and below, that’s when it get worse and worse (slowed and jagged). It’s not possible to draw/paint at 45% zoom and below. In fact, zooming, rotating and panning is extremely slow at 45% and below.
2) When “Canvas Graphics Acceleration” is UNCHECKED:
At 45% and below, even down to 1% of zoom level, brush stroke is still good. Even with the “Basic-5 Size Opacity” brush. Panning the Canvas is a lot better, regardless of the zoom level. BUT, zooming and rotating the Canvas is bad.
There’s another one that is not mentioned above, such as drawing while the Canvas is in a rotated state.
I was given an external GPU (Radeon VII) to test it out via Thunderbolt 3, still no help. It looks like Krita is not optimized for AMD GPU on macOS.
As of May 20th, 2019, my best option is: Uncheck “Canvas Graphics Acceleration” and Canvas must not exceed 10,000 x 10,000 px @ 300dpi. To zoom in/out, I must use the keyboard “-” / “+” (it still lag a bit, but not much compared to doing it via mouse scroll or tablet pen). Overall, things still lag a bit, but it’s more bearable.
UPDATE: So, even with “Canvas Graphics Acceleration” unchecked, you run into another problem. Drawing while the Canvas is in a rotated state. The dimension of this Canvas is 3508×1960 @ 72dpi. In the image below, the top is with “Canvas Graphics Acceleration” checked. The bottom is what happens when you uncheck it. This mean that to be able to draw smooth line while the Canvas is rotated, I have to enable graphics acceleration.
UPDATE2: With acceleration enabled, there isn’t any problem if you’re drawing or painting at 100% zoom level. Problems only appear when you’re working at very big size and are zooming out. Generally, I do my sketching at 72dpi. If I need to make broad strokes at big canvas size while zooming out, then I simply disable acceleration. But for now, I leave it enabled since all I’m doing is sketching.