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

Most desktop apps actually don't need to be 64 bits binaries, to the notable exception of image or video processing apps. In contrast, server apps often do.

The best advantage of running on a 64Bits machine a is that your app will have more RAM space, so it won't get swapped away when other apps will need the RAM. Yet 32 bit apps run on 64bits machine (luckily enough). I'm typing this on a 16GB Linux laptop with 2 DB (Oracle 11g and Mysql 6.0alpha), Windows in VirtualBox and a host of Java VMs, eclipse with Xmx=2GB...) and I couldn't cram all this on 4GB. Yet I still prefer to run 32bits apps when they do not need large amount of memory space.