There’s so much detailed documentation on these methods, such as here:
with notes about how it behaves on different types of objects.
I’m not sure what more you expect anyone here to add.
As for “faster,” DO NOT OPTIMIZE CODE JUST BECAUSE… If you don’t have a problem, DO NOT OPTIMIZE!
If you DO have a problem, there is only ONE way to find out. Always start by using the profiler:
Window → Analysis → Profiler
Failure to use the profiler first means you’re just guessing, making a mess of your code for no good reason.
Remember that optimized code is ALWAYS harder to work with and more brittle, making subsequent feature development difficult or impossible, or incurring massive technical debt on future development.
Notes on optimizing UnityEngine.UI setups:
At a minimum you want to clearly understand what performance issues you are having:
- running too slowly?
- loading too slowly?
- using too much runtime memory?
- final bundle too large?
- too much network traffic?
- something else?
If you are unable to engage the profiler, then your next solution is gross guessing changes, such as “reimport all textures as 32x32 tiny textures” or “replace some complex 3D objects with cubes/capsules” to try and figure out what is bogging you down.
Each experiment you do may give you intel about what is causing the performance issue that you identified. More importantly let you eliminate candidates for optimization. For instance if you swap out your biggest textures with 32x32 stamps and you STILL have a problem, you may be able to eliminate textures as an issue and move onto something else.
This sort of speculative optimization assumes you’re properly using source control so it takes one click to revert to the way your project was before if there is no improvement, while carefully making notes about what you have tried and more importantly what results it has had.