I'm reformatting. Been using Vista x64 for a few years now happily, but I'm looking to squeeze a bit more performance out of FSX (in particular). I'm not exactly complaining about performance now- that is once I turn down my ginormous AI. I've noticed that the latest drivers from ATI have helped too- even on my 2 generation old video card (better general performance with AA/AF)In general on a Q6600 will Vista x32 or x64 OS run faster? I am legal for both :)Hardware is a Q6600, Radeon 3870, 4gb ram.And before you ask, Win 7 is not currently an option for me.Thanks all!

x64 allows your PC to address > 4GB of RAM so there is potential for more performance there, but x64 is not inherently faster than x86 otherwise.

Techguy has it right - In terms of measuring the differences, I think it's been shown that x86 vs x64 doesn't amount to any documented differences in performance. Some (myself included) will state that x64 is superior in overall smoothness for any given FPS rate, but that is subjective. Having used Vista32 and Vista64, I found the 64 edition to be far smoother, even though the framerates were pretty much identical. I now run W7 (x64) and have had nothing but good experiences with it. To me, my W7 experience is smoother still than Vista64. Stick with Vista64 - you will not improve down at Vista32 and you might even take some steps back in how you perceive the smoothness.(I know you stated it's not an option right now, but keep your eyes on W7. When the time comes, it will serve you well!)

A 64-bit OS will give your system access to all 4GB of your installed RAM, which in some circumstances could improve performance. In a 32-bit OS with 4GB of RAM installed, your video RAM and some other hardware resources will block a sizeable portion of your RAM from use. If you have a 512MB video card, that means over 512MB of your 4GB of RAM is rendered unuseable by the system in a 32-bit environment.More importantly, a 64-bit OS combined with a "LARGEADDRESSAWARE"-enabled FS executable nearly eliminates OOM errors. SP2 and/or Acceleration for FSX makes it largeaddress enabled, FS9 must be modded with a simple change to the fs9.exe file to make it largeaddressaware.IMHO, a move from 64-bit to 32-bit would a huge step backwards with no real upside.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

A 64-bit OS will give your system access to all 4GB of your installed RAM, which in some circumstances could improve performance. In a 32-bit OS with 4GB of RAM installed, your video RAM and some other hardware resources will block a sizeable portion of your RAM from use. If you have a 512MB video card, that means over 512MB of your 4GB of RAM is rendered unuseable by the system in a 32-bit environment.More importantly, a 64-bit OS combined with a "LARGEADDRESSAWARE"-enabled FS executable nearly eliminates OOM errors. SP2 and/or Acceleration for FSX makes it largeaddress enabled, FS9 must be modded with a simple change to the fs9.exe file to make it largeaddressaware.IMHO, a move from 64-bit to 32-bit would a huge step backwards with no real upside.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

I've been running both FSX and Vista x64 for years BTW- with no OOM issues. I'm a Windows sys admin by trade so I fully understand memory addressing and usage.I was just curious based on others real world experience. I run XP at work on my desk, Vista x32 on the laptop. We haven't deployed Server 2008 yet, but I have a basic test set up. We have a VMWare project kicking off soon and we'll flip all of our DC's to 08R2 after that completes, then start on an Exchange 2010 project. I'm much less of a home tinkerer than I used to be. Just not enough time anymore being Dad and all.Personally I like the new(er) UI better, but the admin tools are virtually identical.I Just installed Win 7 x64 last night at home, but have barely done more than share out the digital photos and install the 9.9 drivers for my video card. Now it's a matter of seeing how the licensing plays out.

x64

under 4 gigs of ram = 32 bit4 or more = 64 bit....

64 bit. It doesn't only allow you to access more RAM, but in certain areas of computing performance is much better. 64 bits means the processor can access more registers in the the CPU cache and page file or vitual memory of at once and it really shows in programs such as photoshop, sony vegas, etc. Even if you have less than 4GB go with x64 because it will save you a lot of trouble in the future, and also the future is 64 bit programs. Why not use all the power your PC has, instead of waste it by using 32 bit. There is also much more bandwidth in the PC which can mean faster texture loading because the bus sizes that were 32 bits will be higher.More Info: http://en.wikipedia.org/wiki/64-bitForgot to add because of Windows 7 there are many 64 bit drivers, and almost all recent hardware (probably as early as 2002) has the proper drivers, so you shouldn't worry about that. Also all 32-bit programs will run on 64 bit via emulation without any performance decrease!