Do games automatically launch in 64bit mode?

I've been googling this a little bit, but most of the threads I find are none-conclusive.

Do I have to "tell" my game(s) to run in 64bit mode (if supported) or does that happen be itself?

I recently installed windows 7 64bit, and GTA 4 installed with out any complications.

The intalled files ended up in a folder called "program files (x86)" and as fare as I could understand that is becaus the launch files and side applications as "social club" and "windows live" are only able to run in 32bit mode.

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Is there any way of checking if my game is running in 64bit mode?

I don't know how to check if it is, but if you have to you can just run as administrator.

Only games that have 64-bit binaries. GTA4 is not one of them. Only a couple of games support 64-bit. Most games are however, 64-bit compatible which means they run in 32-bit under a 64-bit environment.

The program files (x86) folder is where all the 32-bit programs are located in Windows 64-bit.

the game needs to have 64-bit executable. it can't run in 32-bit and 64-bit mode from the same file. not many games support 64-bit operating systems, but if you know it does, just find the 64-bit executable from the installation folder. i guess the reason is that they haven't been able to gain any real advantage from it, and most systems these days are 32-bit.

i have 64-bit Vista, and i tested this on Crysis. i ran the benchmarks with same settings on 32-bit mode and 64-bit mode, and the 32-bit mode ran few frames better. i don't know if it's just because they haven't properly optimized the game (or the game engine) for 64-bit OS.

No one says anything about ARMA II, but why is it installed in "Program Files" and not in "Program Files 86"? ? No 64bit mode for this game,so why?Starcorps

i dont know anout that game and why is not being installed in 32 bit applications folder but if it was an 64 bit architecture ,it wouldnt run on 32 bit windows and most of us here have 32 bit windows ,xp or vista .( you can install a 32 bit program in vista 64 but you cannot install a x64 architecture program in windows 32 or x86 architecture

the game needs to have 64-bit executable. it can't run in 32-bit and 64-bit mode from the same file. not many games support 64-bit operating systems, but if you know it does, just find the 64-bit executable from the installation folder. i guess the reason is that they haven't been able to gain any real advantage from it, and most systems these days are 32-bit.

i have 64-bit Vista, and i tested this on Crysis. i ran the benchmarks with same settings on 32-bit mode and 64-bit mode, and the 32-bit mode ran few frames better. i don't know if it's just because they haven't properly optimized the game (or the game engine) for 64-bit OS.

prowler666

This, exactly.

This division between 32 and 64-bit is just like it was when the first 32-bit Windows came out. People were wondering if 16-bit games would run as 32-bit, and would the old DOS games still execute.

XP has problems executing 16-bit screensavers (without tweaking), since it is coded to automatically run all screensavers in 32-bit mode.

As stated, a game executes in 64-bit mode only if the executable is written in 64-bit code.