Why does Vista x64 still run x86 applications as Default?

For example, Windows Media Player 11 or Internet Explorer. Whilst x64 versions are installed, Vista by default boots the x86 versions of these applications?

I use Firefox anyway (do they do a x64 version of this??) & I have set Windows Media Player to default to x64 version using a Vista Codec Pack I downloaded.

Are there any other applications that Windows by default uses x86 versions of when it has a x64 version readily available?

Thanks, Chris.

 

Because there aren't many x64 codecs to use with those versions. x64 WMP requires x64 codecs, so there might be problems. Not a big problem, since there are x64 codec packs.
There is a x64 version of Firefox. Start64.com has it.

 

Is there any tangible benefit of running those apps in 64bit versions? I thought that the primary reason for running Vista 64bit was to enable the OS to access RAM in excess of 3GB.

Isn't a 32bit application able to use 4GB memory? If so, should not the "only" reason wanting 64bit versions of software for Vista 64bit be that your apps need more than 4GB memory?

Since few normal apps even come close to using 4GB memory on their own, what point is it to use 64bit versions of Internet Explorer, Firefox, Codecs etc in Vista 64bit?

 

Well theoretically is, but practically a movie woun't play faster with a x64 application.
The point is lower CPU use, as the programs don't have to go trough an extra layer. x86 applications also work faster (a little, unnoticeable bit) on x64 OS.

 

Very interesting!

Do you have any idea on how much CPU overhead is caused in Vista 64bit when running 32bit applications?

 

32bit applications can only address up to 2GB of RAM...

 

I view it quite simply like this. If i've installed a x64 Operating System I am obviously aware of the benefits / negatives of this already so why not just run all of the Applications in their native setting, I really don't see the point in running a x86 Application when a x64 version of the same one is available on you x64 operating system unless compatibility is an issue of course.

Again, are there any other Applications other than WMP and IE that have x64 support in Vista but for some reason are running in x86 mode by default?

 

ive done some 'tinkering' how do i know if something (eg media player) is running 64 bit or not?

 

I stick to 32 bit ones, K-Lite Mega Codec Pack. They're safe and always work.

 

i installed some vista codecs and opened up media player but they didnt work
so i tinkered with the registery as per the other thread and now it works...