Ubuntu 64-bit vs 32-bit
I currently run a Ubuntu system with 32 bit but I have 4 GB of RAM. As I have heard only 3 GB are used. In the recent time I'm seeing that I need more memory. The question is: Should I change to Ubuntu 64 bit? I heard that with a 64 bit system you need twice as much memory as with a 32 bit system so effectively I would have less memory?! In the near future I plan to upgrade my RAM to 6 GB or 8 GB but this wouldn't pay off significantly if this was true, right?
I have seen related questions on this topic, but they weren't that specialized on the memory issue... But if I understand it correctly it also depends on the Applications used: On my computer a lot of memory is used by Web browsers (Chrome, Firefox). But I also use Eclipse and often use VMWare (Windows XP with 1 GB) That sometimes really slows down my system, in particular the VM becomes slow... And I am now working on a project that needs Hadoop, this might also need a reasonable amount of memory...
So my question is: Does it pay of to switch to Ubuntu 64 bit? Or would I need at least 8 GB or 10 GB of memory to have a reasonable payoff?