or put another way as steve beat me to it…
for 100 unopened groups, SU records 100 positions for one set of geometry, without the other info used by components, [a tiny amont] so it will be a slightly smaller file, than 100 [identical in geometry] components…
open one of those groups and SU will record two sets of geometry, and the same 100 positions…
for each group you open SU will add an extra set of geometry [even if identical to the others], but will still record 100 positions…
if you never intend to open any of your 100 groups then the file can be smaller than using 100 components…
if you alter or even open all 100 groups it will be a much larger file then the 100 components…
for file size, the major advantage of components over groups is they can share any changes, so you can modify all but still only have one set of geometry at 100 position increasing file size by only one set of your change…
but for 100 individual groups with the same geometry, you have 100 sets of geometry at 100 positions…
add 10 edges to you component and the file adds ten edges…
add ten edges to 100 groups and the file adds a thousand edges + the number of edges in the original group X 100…
john