64 bit vs 32 bit

[bpm242]

Hello. Can someone help me understand a few things about 64bit vs. 32bit? I understand that one big thing about 64 bit is that it can use more RAM than a 32 bit system. That’s fine...I get it. Here's my question though: what actually happens when I am running a VISTA or Win 7 64bit installation but have 32 bit apps/games? I have not installed any of my VISTA or Win7 64bit versions because I don't know what will happen if/when I use a 32bit App/Game. Will the apps/games "NOT" work at all.....or..... will they simply just "RUN" at 32bit? Will my system crash or be damaged? Can someone please help enlighten me. Thanks.

 

[Guest]

They run in an emulation mode. See: http://en.wikipedia.org/wiki/64-bit

 

[sminlal]

The vast majority of 32-bit programs run just fine in 64-bit Windows. It's a little misleading to say that it's "emulation" mode because they run using native x86 instructions - its only when they make calls to the operating system that any special handling needs to be done to interface with the 64-bit OS.

In fact there are still very few true 64-bit programs around, so that huge majority of programs that everyone uses on 64-bit windows actually 32-bit programs. This will probably continue for several years since most programs are run perfectly well in a relatively small amount of RAM and therefore there's no pressing need for then to use 64-bit code.

The big exception to all this is for device drivers. Device drivers run at the bar-metal hardware level, so they need to be 64-bit in order to run in a 64-bit OS.