4GB is the limit with 32bit. It's starting to be used on servers, so that's an issue there. But even on phones: Moterola Droid 256MB [2009] Google Nexus

4GB is the limit with 32bit. It's starting to be used on servers, so that's an issue there. But even on phones: Moterola Droid 256MB [2009] Google Nexus One 512MB [2010] Galaxy Nexus 1GB [2011] Google Nexus 4 2GB [2012] It doesn't look like it will be long before we need 4GB or more. I would expect, like with x86, you need 64bit even to access the full 4GB (due to memory mapped devices)