Are there a less CPU-intensive units?

[vitaprimo]

On an old MacBook Air remoting-in client, I opened a design directly on it because Affinity Designed isn't very usable over Apple Remote Desktop. It's just some artboards with diagrams on them but they are kind of big. They're more or less 2:1 with 8000-15000+ pixels on the longer side and I did notice it a little sluggish while zooming and panning around, not much though, just on the busier parts an object group would take a second to appear.

They are this big because if smaller, when I really zoom in, moving and placing things gets jankier. It seems like Designer may be treating vectors as raster images or something that's making pixel count in vectors an issue—I think, I don't know.

I tried changing the unit to something else; meters. Everything is under a meter but there are still three decimals in the dimensions, that's too many numbers. Do these changes have any effect at all of how Designer processes things or to I need to resize things? Reduce DPI?

Does snapping work at sub-pixel? Is it affected by DPI?

I'm open do any advice/suggestion. =)

Thanks.

[NotMyFault]

There are several aspects which will lead to slower rendering:

• the resolution of the file counted in pixel, as you observed. All vectors are rasternd during rendering to be displayed, and this about 60-120 times a second. 
• The number of layers. Designer can handle millions of layers in principle, but we had several occasions with files generated by CAD software, using millions of lines (curves with strokes with some overlap) to „simulate“ fills which needed 15 minutes to open.
• The complexity of functions used in the document. Vector brushes are images, repeated or stretched along a vector path. Large brushes can become very slow.
• layer fx, gaussian blur can become extremely slow with very high radius (>>100). This is the reason UI sliders often limits radius to 100, but allows to enter larger values in numeric form.
• Of you „borrow“ filters from Photo, blur and sharpen can be extremely expensive with large radius
• In case you have lots of invisible layers in a file (e.g. a huge layer stack, covered by a opaque rectangle so it has no impact to the rendering result). Lots of artboards. Better try to remove this content from the file, and keep the document lean and clean. We had a report where a user stored all his work in one single file in hundreds of artboards, leading to slowness. For me it seems Designer reads the full layer sequence during opening, and is limited to one core/cpu (not using parallel processing).

So the physical units and dpi are less relevant, but effective size in pixels matters more for performance.

[NotMyFault]

1 hour ago, vitaprimo said:

Does snapping work at sub-pixel? Is it affected by DPI?

Snapping to objects works on sub-pixel.

You may run into issues to define e.g. grid with sub-pixel resolution because of UI limitations, but when you are able it works.