No.

32-bit applications are limited to just 2 Gigs RAM.

Like, when testing my system with 4 gigs, I'd have to load two copies of the 32-bit Prime95 to check the memory, as each 32-bit has a 2 gig limit.

Or, I can just load up 1 copy of the 64-bit version, and it will test it all.

Even a system with 3 Gigs RAM can take advantage of 64-bit Windows.

You're going to be hitting ceilings with 32-bit software at 2, 3, 3.5, 4 gigs, etc. If you're running 4 Gigs or more (ie, LESS THAN 8), 64-bit is a must.

Applications don't know anything about RAM, only virtual address space. They're limited to 4GB of VA, of which 1 or 2GB (depending on if /3GB is used in boot.ini) is used by the kernel, and 2 or 3GB is available to the application. The NT memory manager determines whether those VA pages are mapped into physical RAM or into the pagefile.

I will agree, however, that systems with 2 or 3GB of RAM can still benefit from 64bit Windows, especially when running native 64bit apps (being able to access 64 registers on the CPU instead of 32 can bring great speed increases). I would suggest anyone with 2 or more GB of RAM to consider x64 before making a final decision - if all of your apps will work (or can be made to work), choosing x64 over x86 makes sense. If you have any app compat issues, of course, x86 is still a safe bet.

I just switched to 64-bit in my latest clean installation...with a 2.4GHz Core 2 Quad and 3 GB of RAM, I have noticed no significant performance increases or decreases, and only one minor program didn't work. My system is about one year old, and all major components had 64-bit drivers available - amazingly even my four-year-old Lexmark x5250 all-in-one had a full-featured driver available.

As for major applications, Office 2003, Acrobat 8 Pro, Nero 7 run fine under 64-bit even though none of them were designed with Vista x64 in mind. My only software conflict came with Webroot Window Washer, which Webroot's own site acknowledges is not compatible with 64-bit. Oh well, gave me an excuse to finally move to CCleaner.

If I were building a new system now, even if I wasn't planning on putting in 4GB+ of RAM right away, I'd go ahead and install Vista 64-bit, because as the other posters have acknowledged, with the price of RAM falling rapidly, it won't be long before you're running with 16 GB.

Since Vista is running faster on 64 bits, I imagine it leaves more resources for all apps, 32 bits included.
32 bits apps may not profit from the 64 bits architecture, but they will have more resources like processing power and memory to run.
Am I right?

No, they're still in an emulated 32bit environment. They still have 4GB virtual address space, of which 2GB is available to the app. And they still have access to the same 32 registers that they would on a 32bit box (although wow64 can dynamically assign these to memory above 4GB or to registers not native to 32bit, it's not something the 32bit app can take advantage of - this is done by wow64 purely as a load-balancing feature so as to run *it's* 64bit environment efficiently.

You didn't understand my question:
If Vista64 run faster on 64 bits processor, it uses the processor less often, less intensively, less hindering other apps.

No. x64 will use more RAM if you have it (and the binaries are larger and processes use more space on load, so it will use more memory by default), but having 2 - 4GB of RAM doesn't preclude you from using and benefitting from x64. Ask for an explanation, or if they're just regurgitating something they heard somewhere .

I ran 32 bit Vista Ultimate with 4 gB of RAM - then switched to 64 bit Vista Ultimate with 4 gB of RAM. It wasn't any faster, and may have been a tad bit slower. Then I found this article: http://www.tomshardware.com/reviews/vista-workshop,1775.html

Upgraded to 8 gB of RAM - and it's fantastic. Not significantly faster, but I can leave everything open and still play games without any lag!

OEM's have started to push 64 bit Vista systems over the last month or two. And the rumors about Windows 7 seem to indicate that 64 bit will be the preferred flavor (although 32 bit will be available).

So what worthwhile benefits does x64 have for those with less than 4gb memory?

This post has been edited by anonymous_user: Aug 23 2008, 10:35 PM

Well, a larger kernel memory space, larger process VA space (for native x64 apps), access to 32 additional CPU registers (for native x64 apps, including the OS itself - 32bit apps are limited to the lower 32 registers on the CPU, x64 apps can access all 64), and it's more future-proof (not sure if Win7 will have an x86 flavor or not - current projections are that it actually may not). You also get patchguard, signed driver requirements, and larger RAM headroom if at some point you do want to add more than 4GB (if you do want to upgrade in the future, you cannot upgrade from x86 to x64 - you'd need a clean install). Remember, though, driver support means you need to make sure you have x64 drivers for your hardware before jumping, not to mention you would need x64 versions of any antivirus or firewall product you might use (you can't load 32bit filter drivers in an x64 OS) - I've not found this to be a problem with mainstream apps in this category, but your mileage may vary.

32bit apps will likely not be faster under x64, and you should always check app compat before jumping - however, if you do have 32bit apps that will run, a good video card and CPU, and you can find x64 versions of apps you use if possible, you will find x64 to be just as good, if not better, than x86.

This isn't exactly true in all situations. 32-bit applications that are LAA (large address aware) can address up to 4GB of memory on Windows x64.

I use 32-bit, all of the apps I use are 32-bit and very few have 64-bit versions (well, the only one I can think of that has 64-bit is 7zip--lol) so I don't really see the point. Plus my laptop has 2GB, that's the max and 64MB is for video memory, and apparently I'm not supposed to be running 64-bit with less than 4GB...

This post has been edited by redxii: Nov 20 2008, 07:07 PM

True, but there aren't many. Most apps compiled this way are server-type apps (like SQL Server or Exchange, for instance). I was trying to keep it simple .

A lot of CAD applications are written that way. AutoCAD, Revit, 3DSMax, etc, etc. I deal with all of those on a regular basis

True, AutoCAD was one I remember. Even if you don't have AutoCAD x64, you could still run older versions that are compiled LAA under x64 WOW and get 4GB VA - I know I would .

You can but it serves no purpose. 64-bit apps use slightly more memory because of the x64 overhead. Its like this by design.

Your 2GB just became 1.8GB.

The main benefit for 64bit is access to more than 4 gigs of RAM. With more and more OEMs putting 4 gigs in their computers and with the X58 chipset that supports 24 gigs of system RAM, 64bit is the way to go. Even if you don't plan on adding more memory for a while, I'd still go with Vista 64bit as it's better to have it now and not need it than to need it and not have it. It's a bit faster and a bit more stable than its 32bit counter part.

As another poster stated, if you need something that doesn't work right with it, run a VM and use the software there.


I sure hope so. I think MSFT should start pushing for 64bit to be main stream.

This post has been edited by MrCobra: Nov 23 2008, 11:46 AM