Dubligroups in BGE?

Hey. Just thought to ask which methods would you prefer to optimize your scenes if you know your project would have a lot of objects on it? I know visibility and disabling physics is one, but would such things as dubligroups or something similar work?

Edit 2012/04/06: Clarification, grammar.

Optimisation can mean many things and optimising for one parameter can often mean losing optimal properties in another. With my understanding of ‘Dupligroups’ they will optimise for file size, possibly memory (depending on how they have been implemented) in my experience often the bigger problem with optimisation in BGE projects is that of performance.

I actually ran some tests on this and was surprised by the results, I am running an i7 and a GTX285 I was expecting the number of objects to cause fps drops long before it did , on other CPUs the number of objects may become a problem more quickly. I would add the warning that I saw an unexplained difference between these results in objects created as ico spheres and when created as cubes (cubes being much faster although they were duplicated and contained the same number of triangles???)

The results appear to indicate that there is no real overhead or benefit of objects over dupligroups, blender appears to be pretty efficient at handling large numbers of objects and dupligroups, but if you have to display many hundreds or thousands of objects you may be better off collecting them into a smaller number of larger static objects.

Its also worth mentioning that dupligroups of animated objects dont seam to work.

Test Results
320 triangle object (ico sphere)
5399 dupligroups
Total: 1,728,000 faces
FPS: ~22
note: backface off, starts in about 2 seconds

320 face object
5400 objects
Total: 1,728,000 faces
FPS: ~22
note: backface off, starts in about 8 seconds

1,728,000 face object
1 object
Total: 1,728,000 faces
FPS: ~22
note: backface off, starts in about 8 seconds

12 triangle object (cube)
5400 objects
Total: 64,800 triangles
FPS: 60 (capped)
note: starts in 1 seconds

12 triangle object (cube)
10,800 objects
Total: 129,600 triangles
FPS: ~20
note: starts in 2 seconds

129,600 triangle object (lots of cubes)
1 object
Total: 129,600 triangles
FPS: 60 (capped)
note: starts in 1 seconds

129,600 triangle object (lots of cubes)
3 objects
Total: 388,800 triangles
FPS: 60 (capped)
note: starts in 1 seconds

129,600 triangle object (lots of cubes)
9 objects
Total: 1,166,400 triangles
FPS: 60 (capped)
note: starts in 3 seconds

129,600 triangle object (lots of cubes)
27 objects
Total: 3,499,200
FPS: ~22
note: starts in 12 seconds