Brush painting slow at 1% spacing

Maybe this is just unavoidable, but I’ve noticed that when using the brush tool at 1% spacing, the drawing lags behind the cursor. To really make it painful, try the following brush settings to draw some black on an empty white canvas:

Size: 50
Spacing: 1%
Blending: Source atop

It’s not nearly that slow with normal blending, though still a bit laggy, and at about 5-10% spacing the drawing speed seems fine for all the blend modes I’ve tried.

This is observed on a MacBook Pro with M2 Max, 64GB RAM, 12 core CPU, 38 core GPU, Ventura 13.5.1 (22G90), though it’s been a problem for a few versions of both Ventura and Acorn. Can submit a screen recording if desired.

1% spacing is pretty tight, so there’s a lot more work Acorn has to do there, even with the latest Macs.

With that said, I know I can make things faster in the future, and I really really want to. It’s on the todo list, but I just don’t have a timeline for you yet. As you’ve found, increasing the spacing is the way to go (especially with brushes 20px and up, you don’t really need spacing that tight).