But is it true that a  64 bits Os can allow  2 gb ram each 32 bits softs and you need an 64 bits installation to use more than 2-3 gb of Ram on one computer?
Example:
Hypothese: Two 32-bits softs  and an Os and 4 gb ram installed on motherboard

----On 32 bits system ,like XP ,you can manage 2 and ,with parameters manipulation ,3 gb of ram maximum for loading OS and after the two softs
----On a 64 bits system ,like XP64 or Vista 64 ,you have acces to all the 4 Gb for loading Os and  the 2 soft, each  one can have access to 2 gb max
It is correct ?
If true a 64 bits sys will be better even with 32 bits softs because generally  for the graphics soft the more ram that you can have better it is