# Why is Vista limited to 3gb? **URL:** \ **Category:** Factual Questions\ **Created:** [September 6, 2008, 12:20pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330 "2008-09-06T12:20:38Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [September 6, 2008, 5:22pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/21 "2008-09-06T17:22:24Z")
> [@Quartz](#): > > … > 32 bit apps will not take advantage of a 64 bit platform unless they are recompiled into 64 bit form - the maximum they can see is 4 GB at one time PAE is a workaround but you’re still limited to 4GB at a time. Fortunately, in a 64 bit system, with sufficient RAM, you can have multiple 32 bit apps running each using 4 GB without paging. Which serves most people’s needs. Also note that x64 is the predominant architecture for home machines, and for those, 32 bit compatibility is being handled by the processor, and your 32 bit apps are running about as well as they would on the 32 bit chip. ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [September 6, 2008, 5:36pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/22 "2008-09-06T17:36:34Z")
> [@panamajack](#): > > As for the x86, it refers to the processor’s instruction set . . . The name goes back to the chips based on Intel’s 8086 and successors. The IBM PC used the 80286, and it (and successors) became the dominant standard. A nitpick: the original IBM PC used the Intel 8088. There was no 80286 yet, in 1981. ---
**Author:** ![panamajack](https://avatars.discourse-cdn.com/v4/letter/p/47e85d/32.png) [@panamajack](https://boards.straightdope.com/u/panamajack)\ **Post date:** [September 6, 2008, 10:02pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/23 "2008-09-06T22:02:00Z")
> [@Bytegeist](#): > > A nitpick: the original IBM PC used the Intel 8088. There was no 80286 yet, in 1981. :smack: You’re right. I also discovered something I didn’t know before - the term ‘x86-64’ was actually in use by AMD before they came up with ‘AMD64’. I also wanted to point out that despite this topic digression, the processor doesn’t limit the address space per se; it’s more of a function of the OS. Practically speaking, though, addressing a space larger than the processor word will be prohibitively slow. One thing **Quartz** said applies to Macs as well - currently, if you have more than 4GB installed, each app only gets 4GB maximum. The articles **Sunspace** linked to cover all of this quite well. ---
**Author:** ![troub](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troub/32/14802_2.png) [@troub](https://boards.straightdope.com/u/troub)\ **Post date:** [September 6, 2008, 10:44pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/24 "2008-09-06T22:44:55Z")
True that 32-bit apps generally will run just fine. I just got a laptop with 64-bit Vista, and have so far found the following things I use will not run: - Cisco VPN software (this is a HUGE problem for me) - VMWare (again, not cool, as I’m stuck with using Virtual PC, which sucks for Linux VMs) - Pharos Uniprint client (pay-for-print software for printers at work) I think that’s it so far. The Cisco and VMWare things are irritating because it seems like they’re not even making an effort. I have met my VPN needs by installing 32-bit XP into a Virtual PC and VPNing from inside there. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [September 7, 2008, 12:56am UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/25 "2008-09-07T00:56:28Z")
> [@troub](#): > > True that 32-bit apps generally will run just fine. I just got a laptop with 64-bit Vista, and have so far found the following things I use will not run: > > - Cisco VPN software (this is a HUGE problem for me) > - VMWare (again, not cool, as I’m stuck with using Virtual PC, which sucks for Linux VMs) > - Pharos Uniprint client (pay-for-print software for printers at work) > > I think that’s it so far. The Cisco and VMWare things are irritating because it seems like they’re not even making an effort. I have met my VPN needs by installing 32-bit XP into a Virtual PC and VPNing from inside there. I’m surprised that VMWare does not make a 64-bit version of its software for 64-bit Windows. Makes me wonder what the VMWare Fusion I have on my Mac is. Edit: [VMWare Fusion](http://www.vmware.com/products/fusion/features.html). Says it will let me run 64-bit XP and 32-bit and 64-bit Vista. I’m currently running 32-bit XP in it. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 7, 2008, 3:36am UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/26 "2008-09-07T03:36:44Z")
> [@QuercusMax](#): > > Suppose you have 8GB of real RAM, and another 8GB of swap space, for a total of 16GB. If you actually try to use all 16GB, you will end up with major problems as data gets swapped back and forth between RAM and disk (known as trashing). That’s actually known as **thrashing** , not trashing. Well, unless you’re running a TRS-80… ---
**Author:** ![troub](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troub/32/14802_2.png) [@troub](https://boards.straightdope.com/u/troub)\ **Post date:** [September 7, 2008, 1:04pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/27 "2008-09-07T13:04:38Z")
> [@Sunspace](#): > > I’m surprised that VMWare does not make a 64-bit version of its software for 64-bit Windows. Makes me wonder what the VMWare Fusion I have on my Mac is. > > Edit: [VMWare Fusion](http://www.vmware.com/products/fusion/features.html). Says it will let me run 64-bit XP and 32-bit and 64-bit Vista. I’m currently running 32-bit XP in it. I’m surprised too, but it seems to have something to do with the driver signing for the virtual network cards. Since Microsoft essentially makes a competing product (that of course works flawlessly, unless you’re trying to set up a Linux VM), that makes it a little less surprising that they wouldn’t be in a hurry to just sign the stupid drivers already. By the way, I did find out when I was figuring this stuff out that if you press F8 during startup, you can disable the signed drivers requirement, but only for that sessions. So, I could do that and install VMWare just fine. But then every time I reboot my computer I would have to interrupt the startup and turn off the signed driver requirement if I wanted to _run_ VMWare. There might be a switch that could go in the boot.ini file but I haven’t looked into it that closely. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [September 7, 2008, 3:52pm UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/28 "2008-09-07T15:52:57Z")
I’m running VMware Workstation 6 on Vista x64 with no problems at all. ---
**Author:** ![troub](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troub/32/14802_2.png) [@troub](https://boards.straightdope.com/u/troub)\ **Post date:** [September 8, 2008, 3:48am UTC](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330/29 "2008-09-08T03:48:36Z")
> [@yoyodyne](#): > > I’m running VMware Workstation 6 on Vista x64 with no problems at all. Then maybe it’s just VMware Server. I tried installing VMWare Server, newest version, and it gave me some stuff about unsigned drivers and basically failed the installation. Then, I noticed that any CD I inserted into my drive from then on kept being treated as an empty writable CD. I found information that this is common with these botched VMWare installs, and the workaround is to uninstall and reinstall the CD drive in device manager. I had to do this twice, I think it’s finally back to normal now. I don’t mind Vista overall, but when something doesn’t work, it seems to fail spectacularly. [Previous page](https://boards.straightdope.com/t/why-is-vista-limited-to-3gb/462330.md?page=1)