Advantages of a 64 bit system

Question

From a developer perspective i am trying to understand , what is the selling point of a 64-bit system ?

I understand that more registers are at your disposal , more

Answer 1

As you said, more memory can be a big advantage. For 32bit systems you'll be limited to processes max 4GB (or even 2 or 3, depending how annoying your OS is).

64bits is double the amount of bytes per instruction, so you have more bandwith internally. eg: faster everything.

see also: http://lifehacker.com/5431284/the-lifehacker-guide-to-64+bit-vs-32+bit-operating-systems