Thanks your your reply guys!! Making the offscreen texture bigger will not work for me because I want to support high zoom levels. (Comparable to GoodNotes for example). First I tried rendering directly everything. But I included some profiler Images while panning and while drawing. There are about 16651560 Vertices on the screen. This might be overkill for a drawing / writing app but other Drawing apps can handle this many lines. But with this many Vertices the FPS starts to drop to 30. I don't really know what else of the rendering part could be improved and it does make sense to paste all my rendering code in here, but if you need a specific part I can of course provide it. Profiler while panning Profiler while drawing I draw to the offscreen so I only need to draw the new line onto the texture. Reference Image of the profiled State Those were about 16651560 vertices.

Ok I think this might be bug. Since Xcode 14 beta 1 (https://xcodereleases.com) I don't see this warning anymore.