Comment by rythie
17 years ago
You need it to take advantage of 4GB+ of memory really - so that's most systems you see in shops already. 64bit took off in Enterprise systems (IBM/Sun/SGI etc.) where it was common to have 4GB+ of memory years ago. The Desktop is next. 64bit will come to mobile/embedded when they have 4GB+ of memory.
The Windows and Mac OS ecosystems (particularly drivers) need to catch up with 64bit support, currently this is still spotty which is inhibiting adoption. Linux support driver support for 64bit is excellent due to most drivers being open source - but most people are not using Linux.
You don't need 64bit to take advantage of 4GB+. Only really necessary if you want to address 4GB+ at the same time in the same process.
Yes I know. But if you are running a game on a PC with 8GB of memory and the game can only use 4GB of that (actually 2.7GB in windows), it's not really taking advantage of it, is it?
Also consumer versions of 32bit Windows don't support PAE so only see 4GB of memory (actually 3.5GB after memory mapping of hardware devices) http://en.wikipedia.org/wiki/Physical_Address_Extension and http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx