I'm building a new system, and am trying to decide which OS to install on it. I have two nVIDIA 9800 GX2 video cards, for a total of 4 GPUs. But the drivers to support that functionality are only available for M$ Vista. I'd like to be able to utilize the 64 bit processor (Q9300), but not if nothing under the sun has drivers that'll run in a 64 bit environment (which still seems to be the case). I have toyed with x86 and x64 XP, and it brought something else to my attention - the RAM. I have 4 gigs installed, but 32 bit XP only recognized about 2.5GB of that ram. XPx64 saw all 4GB. So, will a 32 bit version of Vista recognize all 4 gigs? If not, i am stuck with either more RAM than I can use, or a video card i can't use. I'd like to avoid installing Vista 64 bit, because I would like to be able to install something else -- anything else -- from 3rd party vendors. And if people can't even program drivers for 32bit Vista, i shudder to think about the compatability issues on 64 bit Vista... So, to review: 1) It looks like to support all 4 GPUs, i need Vista (32bit or 64 bit). 2) I have 4 gigs of ram. will Vista 32bit see them? also, please don't flame me or anything. it makes us all look bad, and it doesn't help anyone. Thanks in advance.

get the 64 bit version of vista premium or ultimate, what ever you decide. In any case you can run any program under compatibility mode windows xp sp2 32 bit mode. If you want to utilize all the 4 gigs of ram that you have good luck. I haven't had any problem with it. Jim R

According to this M$ article for both 32-bit & 64-bit Windows Vista: 1. When you upgrade to Vista SP1, the 4GB RAM will be reported as installed in the following places: a) Welcome Center RAM value b) My Computer memory value c) System Properties memory RAM d) msconflg System Information tool 2. At the same time, Vista SP1 will not report 4GB RAM installed in the following places: a) Task Manager b) Winver c) DirectX Diagnostic Tool DXDiag.exe The bottom line is that you will have about 3454MB of system memory available to you on a computer that has 4GB (4096MB) of memory installed. i_Xp/VistaUser

With Vista, your x64 license is also valid for an x86 installation, so you can use the same key either way. From first hand experience with both Vista x64 & x32, I can tell you, there is a vast difference in 64-bit hardware/software & driver support between XP & Vista. I have yet to run into one compliance or support issue since I switched from Vista x86 to x64. Although, I don't run applications -- as of yet -- that requires or will take advantage of me having 4GB of RAM & probably could have been just fine with Vista x86; I switched to Vista 64-bit partly because I really had nothing to lose - virtually all my 32-bit applications works just fine via the emulation layer & of course the improved vendor support. My recommendation is: Go for Vista 64-bit, but realize that, while there is the potential for a performance boost with your move to Vista x64, you may or may not reap significant benefits from it depending on the application's use & implementation. Jabbering Idiots: Everywhere You Look!

And don't double post! "And that's the fishing line, because Sharkboy said so!"

Go for Vista 64 Ultimate. The 64 bit version supports more memory as noted above. I now have 8 gig ram with no page file. The machine seems to be faster. And the Ultimate version supports the little extras like Dynamic disks which is great for spanning volumes and drives.