x64 - x86 memory pointers

[Uhtred]

Before you all jump on me this is a slightly different thread!

I know there are some clever chaps on here so i was wondering if you could have a look at the following document for me

http://www.ideateinc.com/whitepapers/all/Inventor - Large Assemblies with x64 Computers.pdf
Take note of where it says "The x64 computer generally requires twice as much RAM to load the same amount of user and program data into memory."

My work college says this is due to memory pointers. Now i know that statement is not entirely true and there are some other mistakes in that article as well (SIMMS anyone). I need to prove my college wrong but i'm having a hard time finding any references on this subject

 

[Uhtred]

That's what i thought. What i wanted to prove was that it wasn't double and more likely to be around 25% like you said.

However the programme in question, inventor 2009 is native 64bit and can use more than 4GB VM (and will do with big assemblies) so am i'm thinking that this could be closer to 100%?