32-Bit Vista Memory Limits



I just got finished building myself a new system…to bad for me that I didn’t think to look and see if Vista had a memory maximux. I purchased the full retail version of Vista Ultimate. My new system has 4GB of physical ram…Vista varys betwee bootups between 3.34 or 3.25 GB of ram. I, like many others see all the ram in bios but not in the OS. I have an Intel 975xbx2 MB, Core2 DUO@2.93Ghz /w 4MB L2, PCI-E Radeon x1950 Pro 256 MB and 2 other addin cards.

Here is my question…does it have any effect on the OS or at the hardware layer to run in this configuration?

Observation/Frustration…Why,in 2007…with the tecnology level that is available today…are we still forced to deal withe the same basic issues that we had since the 8088 processor. I’ve read alot of the other post and also HPs’ responce and it almost sounds as though its…physical ram(4 GB) minus address space of all addin cards equals Vista ram…am I wrong?



Sucks, eh? As you probably read in this post, the “4GB” maximum memory limit of 32-bit Windows is purely theoretical. In practice, the max memory is something significantly less, equal to 4GB minus your video card memory and the address space allocated to a couple other hardware resourcse. Typically, the realistic maximum memory is somewhere betwee 2.5GB and 3.5GB.

Unfortunately, a lot of people are discovering this AFTER they pay for 4GB of RAM. For the record, this limitation has always been there, including in Windows XP and earlier versions of Windows. However, nowadays, more computer hardware is designed to support 4GB or more of RAM, and memory is getting cheap enough that more people can afford the full 4GB.

To answer your question, “does it have any effect on the OS or at the hardware layer to run in this configuration?”: It has no effect whatsoever. It’ll behave just like the unused memory wasn’t physically present.

To address your “Observation/Frustration”, we’re still forced to deal with the same basic issues that we had since the 8088 processor because we still need backwards compatibility. People want to be able to run the same 32-bit programs they’ve used for a decade, and that’s very possible with 32-bit Windows Vista (ok, well, there are some compatibility problems, but most things do still work). If you’re willing to give up that backwards compatibility to shake yourself free of the limits of 32-bit, just install 64-bit Windows Vista. The technology is certainly there, and nobody is forcing you to use 32-bit. However, 64-bit has it’s own problems because it lacks the full backwards compatibility provided by 32-bit. You do have a choice, but most people are still better off dealing with the limits of 32-bit than using 64-bit–which is still “bleeding edge”, despite the fact that it has been around for years now.

Re, “it almost sounds as though its…physical ram(4 GB) minus address space of all addin cards equals Vista ram…am I wrong?”… You’re exactly right. Well, 4GB minus the address space required by addin cards and other hardware equals the MAXIMUM addressable Vista RAM.

Hey, on the upside, the 750MB of RAM you’re missing really wouldn’t have made that much difference anyway. :)

84 Responses to “32-Bit Vista Memory Limits”

  1. Alice M Schumm says:

    But I am only showing 2047 of 4gb… That’s a lot of slippage. I should be seeing at least 2.5…

    Any ideas?
    Thank you.

  2. Rick Kop says:

    I’ve got the same problem, sort of. I’m running Vista ultimate with 4 gigof ram. Ony shows 3

  3. Rob Delaney says:

    Right, could someone answer me this:

    I’m about to put a new systems together, with Vista Ultimate 32. I’m going to get 4gb ram regardless.

    1. Does it make any difference if I get 4 sticks of 1gb, or 2 sticks of 2gb? (ignoring whether all 4 will be recognised or used or not: for the stuff that WILL be recognised, will it make any difference?)

    2. From what I understand, the ram that you “lose” is equal to the video card memory, plus some other bits and bobs. Am I right in assuming that you would “lose” that ANYWAY, if you had 2, 3 or 4gb ram? And does the “lost” ram mirroring the memory from the video card, etc, actually help system performance in any way (i don’t know, by caching or something?)

    I’m perfectly happy putting a machine together, but the mysteries of memory usage are beyond me.

  4. Scotteq says:

    A month late…. But:

    The registry in a 32 bit OS can assign addresses to 2^32 (2 to the 32nd power) worth of addresses. This is 4GB. That is all the space the system has to assign locatable addresses to any system (Mobo) memory, devices, video memory, as well as the physical DIMMS you have installed.

    When the OS runs out of addresses, that’s it.

    The good news is that, unless you’re a gamer or do things like video encoding at home, you’ll not need more than 2GB to run nearly anything that’s on the market today. If you *are* a gamer or Video enthusiast, DDR2 RAM is cheap enough to be worthwhile to buy the 4 Gig worth and live with the 2.5~3.25 usable you’ll achieve with the upgrade.

    If you need more, the alternative is to move to a 64 bit OS, who’s registry can address 2^64 (17,179,869,184 gigabytes) worth of space.

  5. James Habeck says:

    I can live with 3 g of memory, but if I install more than 2 g on Vista Ultimate 32 bit it won’t boot.

  6. James Habeck says:

    After installing Microsoft patch KB 929777 I am now able to install 3 each 1 G sticks using 3 slots and still be able to boot. When I try to install 4/th 1 G stick using the 4/th slot; can’t boot. The 3 G shows up as usable on my Computer properties. Even though I can only use approx. 3.5 G on vista 32 bit, I have purchased 4 one G sticks and would like to fill up my 4 slots. Help

  7. Chuck Smith says:

    is it possible that there is gonna be a patch for windows vista and xp to support 4gb physical plus the videocards and stuff because im having the same problem

    my specs
    2.86 ghz x2 amd 4800+
    4gb pc2 6400 ddr2 800
    512mb video geforce 7300 gs PCI-E
    620 gb harddrive space
    10/100/1000 ethernet
    Lite-On dvd Dual-layer burner

  8. D. says:

    I installed 2x2GB sticks on my Pavilion laptop, Bios would only see 3.2GB and Vista would not boot, upgraded Bios and 4GB were visible by Bios, Vista booted but only sees 3GB…

    Maybe someone someday will come up with a solution to this…

  9. Ehlo says:

    Simply there is only one solution, this was said in the original post.

    64Bit Windows.

    The inability to for the OS to address more than 3GB of ram is a 32bit addressing system limitation. Yes, windows server 2003 enterprise can see up to 16GB of ram with the 3GB switch in the boot.ini, the OS still physically cannot address more than 3GB of ram, there are additional switches to allow for SQL and exchange to address it’s own block of 3GB, a 64bit OS is the only option for addressing more than 3GB and up to i think 64GB (I STAND TO BE CORRECTED).

    Unfortunately for us, Vista does not have a BOOT.INI, so we cant even play around with the 3GB switch option.

    Just run 64bit, I am, and I am a gamer. The only game that i have a problem running so far is Battlefield 2

  10. RAM says:


    I am planning to buy a dell latitude notebook with 4GB RAM – Vista ultimate (32bit). In the website dell does not stop me in configuring for 4GB RAM but do you have any idea about the performance of the laptop with above config.? I wonder as some part of the RAM will not be of any use? Plese suggest !!i

  11. jeffc says:

    If you get your Dell with 4G and Vista Ultimate 32bit your laptop will see only about 3.5G MAX (could be less).

    In my experience, I’ve always been able to get part of that last 1G of RAM to be in use, but YOU WILL NEVER BE ABLE TO USE ALL OF THE 4G.

    This is not a bug, issue, or whatever. MS will not be issuing a patch for this. All 32bit OS can only address 4G of memory space, and part is reserved for BIOS and other hardware.

    64bit Vista is a good option if your software will run on it.

  12. James Habeck says:

    Dell will be happy to sell you whatever you want, but your system will only be able to utilize about 3G. if you purchase a 32 bit OS.

  13. Nel says:

    Currenly my laptop is using 3gb of ram and another 3440 mb of readyboost on my vista32 bit and my bios shows that i have 3061.15mb, available physical memory of 1.82gb, total virtual memory of 6.16gb, available virtual memory of 4.96gb and page file space of 3.28gb. I m planning to get another gb and try on my santa rosa before christmas , do u think my system will capture my 4gb? Any idea ?? Thanks

  14. George says:

    The problem isn’t backwards compatibility, it’s the poor design of Windows. Mac OS X and associated programs run equally well on 32- and 64-bit systems. 32-bit Windows users are all going to have to dump their current operating system, drivers, and programs, and get 64-bit versions in order to go beyond about 3GB. (Or get a Mac?)

  15. DraX says:

    It’s not so much a windows issue as it is a development platform issue and an issue with the lack of driver support.
    Since there is not as robust of driver support (yet) for 64-bit windows, it’s much harder for developers to program equally for 32 and 64 bit.

    Eventually, programming for 64 bit will be more or less a requirement, but I doubt we’re likely to see that in full until the next generation (not the current state of the art) of OSs and systems.

  16. Bruce says:

    Yeah, the 4gb isnt made accessible by wether its vista or XP, its accessible because of the 64 bit tidbit of the operating system :p

    For those who have problems

    For the record, I’m using 32 bit XP corporate professional with a 512MB video card and this system is reading 3.5GB of RAM in Windows.. mines working properly I guess

  17. Rich says:

    I’m truly shocked at the apparent inability of most people to grasp the problem at hand here. no 32 bit operating system will be able to see more than 4 GB total memory of any sorts. This means if you plug a 640MB video card in, a 32MB sound card, and have assorted ROM and cache on your motherboard equalling about 16 MB, the most of your RAM you’ll be able to see is 4096MB – 640MB – 32 – 16, or, approximately 3408MB. If you’re running SLI 640MB video cards, you’ll be lucky to get 2.7gig of your 4 gigs. SLI 768 cards, you’ll be lucky to see 2.2GB. There is no fix, no magical patch, or ability for any general use 32bit operating system to go beyond this number. OS X may be able to address more RAM, but lets face it; until Apple releases it for use on any hardware set, its practicality in real applications, and business uses will be limited to small groups who have more money to spend on overpriced computers, than on some basic research.

    Think of it this way. If you have 1 book of stamps with 20 stamps in it, and 28 envelopes to mail, you will only be able to mail 20 of those envelopes with that book of stamps. No matter what you try to do, you will not be able to mail those other 8 envelopes with that book of stamps. The memory addressing problem works the same way.

  18. Larry Camp says:

    Futureshop has just put 2GB laptop RAM on sale for $90. I am currently using an HP Pavillion dv9000, AMD 64×2 1.6Ghz dual processor. I am running Vista Home Premium, 32-bit. The HP BIOS is F.3D. When I bought it, I ugraded from 1GB (512×2) to 2GB (1GBx2). The salesman told me it was exapandable to 4GB, but only when 2GB RAM became available. Before rushing out and buying new RAM, I came across several post sites such as this one. I have 2 questions:

    1) Although my 32-bit system will never recognize the full 4GB of RAM, I will still need to put in 4GB in order to get the maximum amount, which could range anywhere from 2.5 – 3.5 GB. Obviously, it will not show 3.5GB if I only have 3GB installed? Correct? Curiously, my HP “system” screen show 2GB as a maximum, but I have heard that the latest updates allow for 4GB, even though the system reporting software may not ever show 4GB. It will show up in the BIOS, however.

    2) With 2 slots, would I lose efficiency if I only expand 1 slot to 2GB, leaving the other at 1GB? Or, do I have to expand equally for maximum efficiency?

  19. Larry Camp says:

    Follow up: My need to upgrade my RAM comes from my system performance info, which shows that, with only IE operating, I have 1982MB of Physical Memory, with 1424MB Cached and only 50MB Free. Although there is only one “task” listed, there are about 80 “processes” being used. Other than increasing the RAM as suggested in my previous post, is there anything else I can do to free up some RAM???

  20. HAROLD says:

    I HAVE A PROBLEM WITH MY COMPUTER SHOWING 3GB. with vista o/s. its showing 3046MB

  21. dude says:

    enable PAE mode and you will see all of your memory. this has been in place since early XP SP1 32 bit

  22. kjm says:

    If you boost the virtual memory size, will the remaining memory that was not able to be used, be useable, therefor making most of the memory functionable?

  23. NasaX says:

    ok i understendthet if you got 4g of ram you will get lowere for some stuped tings like address space .
    But how can the DRV explayn thet wen we got 2 g ofram the PC is not saving ram for address space ???
    I mean in the end the DRVs are laing or wat ?

    And olso i stil dont see how can the windwos see more ram memory then the BIOS in the end the BIOS is the one thet starts all hardware and checs all !!!!!!!!!

  24. Rich says:

    oh my god why can so many of you not grasp such a simple concept??? Let’s try again!

    A 32bit system is CAPABLE of using a maximum of 2^32 (two to the power of 32) bytes of memory = 4294967296 bytes = 4GB. This 4 GB limit includes ALL the memory installed ANYWHERE in your box (including therefore any memory on “additional” components such as graphics cards). Therefore if you have a 512MB graphics card installed, your computer can utilise this and a further 3.5GB of memory (that 4GB – 512MB = 3.5GB). Other components also have memory which adds up WHICH IS WHY, although the computer will support 4GB of memory, by the time it has allocated all the memory of the installed components, it usually has a capacity of between 2.5GB and 3.5GB remaining which it uses to recognise system memory (the 4GB or however much you have installed into your motherboard in the form of DIMMs).

    I grant there are briefer ways to describe that but most of you seem unable to understand it when you are told in brief. Either that or you have just been too lazy to read the article and other comments above!

    For your info, I am running Vista x64 with 4GB of system memory but due to compatible issues I am changing to Vista x86 and am fully prepared to accept that I may not get full use of the memory I have installed.

    Microsofts guideline maximum memory limit for ANY 32bit operating system is 3GB. Anyone too lazy or stupid to upgrade memory without checking compatibility deserves what they get – would you buy an external device that requires firewire if you neither knew what firewire was nor knew if you had it?! Do your homework because computers are not rocket science, all the info is readily available for those that are prepared to look and aren’t reliant on being spoon fed (eg lazy!).

  25. mike says:

    I HAVE A PROBLEM WITH MY COMPUTER SHOWING 3GB. with vista o/s. its showing 3046MB
    3072mb=3gig, your fine

    ollow up: My need to upgrade my RAM comes from my system performance info, which shows that, with only IE operating, I have 1982MB of Physical Memory, with 1424MB Cached and only 50MB Free. Although there is only one “task” listed, there are about 80 “processes” being used. Other than increasing the RAM as suggested in my previous post, is there anything else I can do to free up some RAM???

    shut down some of the processes, theres a list online somewhere that describes which are need and which are not.

    ok i understendthet if you got 4g of ram you will get lowere for some stuped tings like address space .
    But how can the DRV explayn thet wen we got 2 g ofram the PC is not saving ram for address space ???
    I mean in the end the DRVs are laing or wat ?

    And olso i stil dont see how can the windwos see more ram memory then the BIOS in the end the BIOS is the one thet starts all hardware and checs all !!!!!!!!!
    bios will read the full ram, 32-bit os does not know what do past a certain amount of ram.

  26. Armand Banana says:

    Arg. Simply trying to “grasp” the concept that A-hole salesmen at Best Buy and HP and SONY and DELL always happily sell you more than you need. The website could simply bring up a red flag and warn you the fourth gig doesn’t function on a 32-bit OS. Selling some horny gamer a 2GB SLI system with 4GB of fast RAM and a 32-bit OS basically amounts to lying, cheating, and stealing (I am not that horny gamer, btw). :)

  27. Bob says:

    Actually, if you have a system with 4 slots, capable of running in dual-channel mode, filling all four slots with 1GB modules, even though the machine may not recognize more than 3GB, should be faster than just installing 3 x 1GB sticks.

    Dual-channel mode is a BIOS function. If you only have 3 slots filled, the RAM will not run in dual-channel mode, and will probably be slower, even though the effective memory amount for Windows is the same.

  28. Mike says:

    What is so hard to understand about memory addressing? A 32-bit computer system can’t address that much memory. People need to start trying to understand the technology they are using. If you want the 4th GB of memory upgrade to a 64-bit version of the OS. Then again, you then have the misery of many vendors not providing 64-bit Vista drivers.

  29. Morai says:

    To Rich,

    Many thanks a lot for your comment. It helped me a lot to understand the underlaying problem of memory limitation for 32bit OS.

  30. Malik Dotiwala says:

    To Rich,

    Thanks for the information; It really helped me a lot also

  31. Bill says:

    Despite the Windows address space limitations, would it still make sense to use 4GB Ram on Windows XP Pro if one plans to create a Ram Disk? Can such a “vrtual” drive somehow take advantage of the “missing” space invisible to the operating system itself?

  32. Kenny says:

    If u have a 32 bit Vista system now can u upgrade that to a 64 bit vista system?

  33. Jester says:

    No Bill,

    no matter how you fry it, the extra memory is simply not accessible, nor addressable.

    besides, I have yet to see any reason to use a software RAM drive.

  34. Mike S says:

    It must not be “Minus The Video Card Ram” as I have a 768MB Video Adapter and I show 3581MB (3.5GB) of RAM in Vista. I think the proper formula has to do with Shared RAM allocation for Video, not the Video adapter’s RAM.

    If this is true, which I believe it is, the Question the would be “How do I de-allocate the shared Video RAM?” Which would be good as my Video RAM is DDR3 and my System RAM is DDR2 and at a slow clock speed.

    You know anything to speed up the bench mark scores and truly take advantage of the video card I purchased.

  35. Kid_puma says:

    Can anyone confirm that the 64-Bit OS/Vista will run 4GB +

  36. Kijak says:

    Yes, I run Vista 64, with 6 Gig of ram and all of it is reported

  37. XTREME says:

    ok, so i in total just finished my system which includes the following: 700w ocz psu, q6700, 4x 1gb of PC2 8500, 64gb samsung solid state hard drive with 32bit vista home prem, creative xfi-fatlity sound card with 64mb ram, 9800gx2 all is on a 780i sli and in an antec 900, after instal of os every driver to date 04/05/07 or today is installed for video card sound card and mother board and with this corsair ram i ordered i did a mem test( memtest86) no errors all is good first load after all drivers are installed bios picks up 4gb ram but when vista loads up i dxdiag only sees 2.302 gbs or 2302mb of ram is this right or is my board bad?

  38. XTREME says:

    oh and bios was flashed to p04 which is latest atm

  39. Bruce_W says:

    The google link to you says Vista can use up to 128 Gb RAM, but all your answers about maximum RAM talk about 4 Gig RAM? Is this because mother boards only support 4 Gig now?

  40. BP says:

    Yes, I understand 64bit can see more ram then 32bit; but does it have the same memory space issue where part of the RAM reserved for BIOS and other hardware?

    For example, if I have 6Gig recognized in Vista64 and a 512MB video card, will the OS be able to use all 6Gig, or is it more like 5.3-something after it’s done addressing BIOS and other hardware just like the examples here with the 32 bit OS?

  41. Xander says:

    Not usually unless you push up to it’s addressable memory limit which no consumer pc will come close to, the reason why is that a 32 bit os is like a 1 litre bottle of water try to pour and imagine main memory is vodka and the sum total of other card’s etc such as graphics card is coke, now the other stuff/card’s always gets poured in the bottle first, so after that then then the system ram get’s poured in… alas with 4gb of system ram it’s like an entire litre being poured into the 1 liter glass, which is already partially full so all extra beyond 1 litre spills on the floor and is wasted, from a practical stand point theres no good reason.

    HOWEVER microsoft & nvidia(cant tell you on ati yet) like’s the idea of adding extra system ram to graphics ram irregardless of the problems doing so it can cause(such as issues with the gddr and your ram running at different rates and so on check the nvidia forums and you’ll find a massive issue suffered by many 8x series users) and they don’t give you option to disable it, if you use an an nvida 8800 gtx for instance i have have (two of em infact) on main pc (also runs vista 64 bit) it can claim 1.5Gb’s of space, with one card or 3GB with two… it does appear to claim the extra space from swap or only when in use, but ideally short of a way to turn off graphics memory sharing, your best off when running beasty graphics card’s on a 64 bit machine to bugger the 4 gig and go for the 8,

    The problem with most 8 nowday’s is simply it’s mostly only available at slower speed’s however 8GB of DDR2 and 667mhz (pretty much the defacto standard of 2GB stick’s(4x2GB) is still practically fast, and with so much of it, you can use hugeo graphics card’s and still have enough ram to turn off swap without ill effects if you want to entirely which will speed your system up, and vastly reduce all that hissing grinding you’ll hear your hard drive making when doing to allot of multi-tasking or making major use of your pc not to mention speed it up.

    Bear in mind with 4GB ram and 2x 768mb(each) graphics card’s vista automatically created 8GB of swap (though obviously it’s unlikely to get near to using it all) So even hogging 1.5Gig’s of system ram for extra graphic’s 6.5 gig’s remaining will be plenty enough for almost all folk’s and eliminating swap has advantages all on its own.

    Many modern higher end motherboards support 8 Gb’s of ram nowday’s Bruce and as only folks running 64 bit os’s which are still a minority can support it’s rarely discussed, however with the small exception of a couple of games which use unsupported by vista driver’s such as security proggies like that with spellforce etc, you’ll find pretty much all games certainly all the worthwile ones work nowday’s sometimes patching is in issue (for instance C&C 3 run fine but if you try to patch it with the official patch it won’t run citing incompatible os, but if you unzip the patch file yourself and manually patch it the patch also work’s fine, it’s stupid really as theres no reason atall to prevent 64 bit from using the file, so even the few issues that do pop up can be solved with a little ingenuity personally for hardcore gamer’s i wholeheartedly recommend it and go for 8gigs it’s usually cheap and well worth it.

  42. Xander says:

    btw just incase i didnt make it clear in last post the 64 bit os can see all 4 gig’s when running it it just uses some of it anyway with a 8800 gtx at least

  43. tim says:

    I have an Asus A8N-E with 4GB installed running Vista x86. My problem is that I’m only showing 2GB of Total Physical Memory and 1.3GB Available. Boot-up and BIOS show 4GB. My graphics card is 512MB, therefore shouldn’t I be showing at least 3GB Total Physical?

  44. billy bob says:

    WINDOWS sucks, can you beleive we are still dependent on BS like this???? Why dont we all buy a MAC and run boot camp with XP, so the rest of this VISTA ***BS*** can go away! BOO BILL GATES AND WINDOZE!

  45. other says:

    Actually billy bob, MAC fails.
    and even linux has this problem.

    It is to do with MEMORY ADDRESSING and 32BIT OPERATING SYSTEMS, not the Operating System itself.

  46. Dr_X says:

    Thank you Other, Billy Bob…. Linux sucks and so does Mac’s one big button mouse….

    If you dont like it…. DONT USE IT!

  47. DJ says:

    im running the 32-bit OS with a 64 X2 Dule Core CPU and 4gig of DDR2 667Mhz Ram the hole 4gig is showing BUT i have this 15 minute boot up WTF some one muct have found a fix by now

  48. Micah says:

    I have two desktop systems… Both 32bit… One runs Debian with the “bigmem” kernel. The other runs the server kernel with bigmem support. Its a 32bit OS… It sees all 8GB.. and I can address it.

    VMWare ESX Server runs on a modified 32bit redhat kernel (they added vmfs support). I have ESX servers with 32GIGS of memory. All 32gigs accounted for.. all 32bit addressable…

    Can you argue this?

  49. rasmasyean says:

    “Hey, on the upside, the 750MB of RAM you’re missing really wouldn’t have made that much difference anyway.”

    This is wrong. The guru is thinking with “XP mentality”. Vista has SuperFetch which can use the extra RAM as HD Cache.

  50. Fab says:

    “Not usually unless you push up to it’s addressable memory limit which no consumer pc will come close to, the reason why is that a 32 bit os is like a 1 litre bottle of water try to pour and imagine main memory is vodka and the sum total of other card’s etc such as graphics card is coke, now the other stuff/card’s always gets poured in the bottle first, so after that then then the system ram get’s poured in… alas with 4gb of system ram it’s like an entire litre being poured into the 1 liter glass, which is already partially full so all extra beyond 1 litre spills on the floor and is wasted, from a practical stand point theres no good reason.”

    Yes very good way of putting it, Xander! The only solution then is to get a larger bottle, right? Well then, going 64 bit would basically equate to a larger bottle. But, I’m sure none of here can justify the pricing on a 64 bit version of whichever Vista we want to use. If you already have a 32 bit OS installed, or it came with your system then just stick with it until your needs grow out beyond what it can offer. If you’re a system builder and haven’t dropped the cash yet (and don’t mind paying more for it) go ahead and grab that x64 Vista.

    (I’m dreaming of a free upgrade from Vista Home Premium 32 to x64…maybe that’s asking too much)

  51. rasmasyean says:

    If this is any indication that 64-bit is the wave of the future and 32-bit will be “obsolete”…

    “There appears to be a shift taking place in the PC industry: the move from 32-bit to 64-bit PCs.
    We’ve been tracking the change by looking at the percentage of 64-bit PCs connecting to Windows Update, and have seen a dramatic increase in recent months. The installed base of 64-bit Windows Vista PCs, as a percentage of all Windows Vista systems, has more than tripled in the U.S. in the last three months, while worldwide adoption has more than doubled during the same period. Another view shows that 20% of new Windows Vista PCs in the U.S. connecting to Windows Update in June were 64-bit PCs, up from just 3% in March. Put more simply, usage of 64-bit Windows Vista is growing much more rapidly than 32-bit. Based on current trends, this growth will accelerate as the retail channel shifts to supplying a rapidly increasing assortment of 64-bit desktops and laptops.”
    -google “windows-vista-64-bit-today”

  52. rasmasyean says:

    @ Fab
    The consumer WILL hit the upper limit.
    Google “SuperFetch increases the performance of Microsoft Windows Vista. You should know how it does it.”

    High RAM will be especially helpful for those people who like to leave all their windows open and use Vista’s “S3 sleep mode” (2 watts) so they can resume where they left off almost immediately after they turn their computers on. Your apps are pre-opened where you left them and your RAM cache is loaded too, just as if you just walked away and came back.

  53. Linux Sucks says:

    As stated by Micah above, 32 bit Linux CAN address more than 4Gb of RAM – 64Gb in fact, on modern CPUs. Looks like Linux doesn’t suck half as much as clueless Windows fanboys do…

  54. Brian Wright says:

    Linux can address more than 4GB of RAM through PAE (look it up). A PAE kernel effectively raises the 32bit address space to 36bit address space and allows up to 64GB of visible RAM on the OS. Microsoft COULD do the same thing with 32 bit Windows and allow more than 4GB of RAM on Windows 32 bit version. Perhaps they will in Windows 7. But, it’s not in Vista 32.

    Note, however, that even if you manage to up the system RAM through PAE to 64GB, you still have 32 bit memory limitations per each application. This means that applications are still limited to a maximum of 2GB addressable memory within its application footprint or 4GB if using PA extensions on a 32 bit OS.

    So, getting the OS to see the RAM is only half the battle. The other half is in getting the applications to be able to use it. This is why 64 bit Vista or 64 bit Linux using 64 bit native apps is the best alternative for maximum memory utilization. Basically, if you have a very memory intensive app, it should be run on a 64 bit OS and application should be compiled natively for that 64 bit OS.

    Note that 32 bit compiled Windows apps can address 4GB of memory space on 64 bit Vista through a similar extension to PAE on Linux. But, this applies to 64 bit Vista when running 32 bit Windows apps compiled in a special way… and yes, Vista 64 does run 32 bit apps fairly well. The main issue with Vista 64 is getting stable drivers.

    • Tony says:

      Vista and 7 support PAE. Applications have to be written specifically to page memory in and out of the PAE-extended memory, however. Apps just don’t take advantage of it.

      Here’s the thing–when a 32-bit app is compiled, it uses 32-bit values to identify memory locations. So, it’ll be limited to the first 4GB of addressable memory. For a 32-bit app to use more than 4GB via PAE, it has to specifically say something like, “Access memory at location 0×329034 in PAE memory page 0×01.”

      For a while, some enterprise server applications (such as Microsoft SQL Server) took advantage of PAE, but once 64-bit OSs were released, developers just started developing for the 64-bit platform.

      So, Vista and 7 support PAE, but it doesn’t really win you anything.

  55. Dave Rave says:

    if I put in 1gb of Ram, the MB posts 1gb of ram
    if I put in 2gb of Ram, the MB posts 2gb of ram
    if I put in 3gb of Ram, the MB posts 3gb of ram
    if I put in 4gb of Ram, the MB posts a number
    somewhat depending on the AGP aperture size, but not, in any way, making sense, of
    posting memory present.
    not what windows uses.
    what is present in the system.
    AGP aperture set to 4mb – 64mb
    system posts 3144640 kb of ram
    set it to 256mb, the number drops.
    about 2.8gb of ram is then avail for windows to use.

    this is the number, before looking at hard drives
    who cares about what OS is used
    my 4gb ram capable MB only posts 3gb of ram

    this board can use 4gb of ram
    4gb of ram is in
    PC Wizard says it has 4 sticks of 1gb ram

    yet it posts, pre-hard drive
    just after turn on
    less than 3gb of ram
    independant of any OS ….
    the OS is only going to see what the MB posts as present

    so don’t tell me a 32 bit system can only see 3gb of ram
    wrong, it’s 4gb

    don’t tell me the OS is hiding it in system utilisation
    the system doesn’t know about anything in the system until after it’s told about the ram available

    this is not ruly a terrible prob.
    just abboying the wrong terminologies being presented all the time.
    memory available is
    pre-system figuring out what goes where


  56. Stephen says:

    You are a one armed postman with a letter carrier bag divided into 4 compartments – 1, 2 , 3 and 4. Each compartment can hold only one letter. You think you can work faster by having water available so you carry a water bottle. Oops it must go in one of the compartments as all you know how to do is address – look into – one of the four compartments. Your speed has improved (that graphics rendering is faster) with the water bottle, but you lost 25% of your letter carrying capacity. So a buddy gives you a one compartment bag to carry in additon. You put a fourth letter in it and now are back to full capacity. But you only have one arm so can only reach your four compartment bag. To get that fourth letter, you must swap one of the other letters or the water bottle from the big bag to the little bag – a bit of a juggling act. You do not necessarily know what is in that new bag, just that you are asked to look for something that is not in you main bag and you wrote yourself a note on one of the letters (some overhead here) to say that you had an “extended” bag. So it is not the most efficient process. This used to be called page mode memory swapping (was it extended or expanded memory in the old 16bit days – I’ve forgotten) but with PAE, 4 extra address lines (32bit extended to 36bit) are used – a physical extension. The upshot is more memory for all the open apps (although still 32 bit per app) at a small cost in overhead – time and some memory. Remember, apps and data are not directly run from the hard drive or CD. These are loaded into addressible memory (RAM). That big hot Intel – or boiling AMD microprocessor creates a 32bit word on its address lines, knocking on the door at that specific address in RAM asking for what is stored inside … which leads to more knocking (even if it already has been pulled into prefetch …) and it goes on.

  57. SmartyPants says:

    Read up on PAE and PSE – linux and mac both can use 4kb/2mb/4mb pages (yes, even the 32bit versions) and can address up to 64GB using page tables/page size extentions – this has been available (in mobo/chipset/cpu) since pentium pro.

    For windoze there are switches in boot.ini for 32bit XP (/pae) and BCDEdit for Vista 32bit (bcdedit /set pae ForceEnable).

    WARNING though – and this is the clincher – not all devices drivers play nicely with PAE so it can lead to system instability – but most newer drivers and hardware support PAE.

  58. Luis Tibayan says:

    My Sony Vaio VGN-CR353 Vista Home Premium 32 bit w/c only shows 3GB of RAM which in fact has 4GB RAM now shows 4GB, after installing all the updates from Windows Update.

    • Tony says:

      The latest Vista service pack shows you the amount of physical memory installed rather than the amount that is usable. Basically, it’s lieing to you. You don’t have any more usable memory than you did before.

  59. PC builder Jay says:

    Heres a solution- DUAL BOOT- use a small HDD or small partion and stick a 32bit vista or xp on it. I heard two versions of vista butt heads more than xp with vista plus xp is alot smaller with simular performance. Use one of the many boot loaders and git er done. Then on with the gaming. I had this problem just because i wanted to use the seirra game Phantasmagoria. I remembered it from win 95 and knew my Girl would love it. Anyway it wont run on my 64 bit vista ultimate.

  60. ssss says:

    This is my Pc:

    Intel® Pentium® 4 Processor 531 with HT technology (3.00GHz, 800MHz, 1MB)

    English Genuine Windows Vista™ Home Basic

    512MB DDR2 533MHz Memory(Qty :2) = 1GB Memory

    256MB nVidia® GeForce® 7300 Turbocache graphics card

    250GB (7200rpm) Serial ATA Hard Drive with 8MB DataBurst™ cache

    It is very slow and all I get is pop-ups. I have MacFee as well. There is 42 updates needed to be installed, but windows dont let me do it. I went on Microsofts website, to help me. I do what they say to do but it still dont let me install the updates. I need HELP ASAP.

    Also do I need more Memory to run vista, people are saying 4GB is the best??


    • Tony says:

      If you’re getting popups and you can’t install updates, that’s a good sign that you have malware (such as spyware or adware). It’s not uncommon for it to defeat anti-malware like your McAfee.

      Sometimes, malware can be removed with anti-malware, and other times it’s very persistent. If I were you, I’d copy all my files to an external drive (or consider using an online backup service if you don’t have an external drive). Then, I’d re-install Windows (or better yet, install Windows 7).

  61. KP: says:

    Want 4GB from Vista or XP? Get rid of the high performance video card (which is memory-mapped for speed), and get a cheap, slow, low-res VGA card. Presto! 4GB memory available. And what will you do with it? Write letters in plain text using a DOS text editor?

    • Tony says:

      It’s true that using a memory card with less memory will leave more for the OS to use (assuming you have 4GB of RAM in a 32-bit OS). It doesn’t mean performance will be terrible, though. 3D games and such might be awful, but standard Windows apps like IE, Firefox, Office, etc., will work just fine.

  62. Ryan says:

    sure is funny that win 32 bit cannot access more than 4 gigs but linux 32 bit can access more with a couple of tweaks

  63. RG says:

    Just finished computer for parents and brothers. Installed Vista Ultimate 32 bit with 8 gigs of RAM. Went to computer properties and all 8 gigs are showing. Did no tweaking. I looked immediately after installation.

    • Tony says:

      Windows might display the amount of physical RAM installed, but 32-bit operating systems are limited to 4GB of addressable memory. So, if you have 8GB installed in your computer, more than half of it is being wasted.

  64. 4g63t says:

    Im running quad core and vista ultimate 32bit. after service pack 2 install and all upgrades my system sees 4gb. before would just be 3.3gb. try it out by doing a full update

    • Tony says:

      This is because Service Pack 2 displays the amount of physical memory installed rather than the amount of usable memory. Your usable memory is still 3.3GB.

  65. Gluttony says:

    Please ca anyone help me? i just purchase a new pc and i can`t
    use my 16Gigs of ram even with Windows 7 Ultimate 64-bits. It`s showing only 3.50 (usable).

    • Tony says:

      Sounds like you’re using the 32-bit version. Do this: Click Start, right-click Computer, and then click Properties. Check the System Type. It should read, “64-bit Operating System” (directly below the amount of memory).

      If you really are using a 64-bit OS, double-check that you have the memory you think you do. If you do, try and upgrade your BIOS.

  66. David Spicer says:

    ok so if you’re running a 32-bit OS and you install say… 8 gb of ram, have 2x2gb video cards… then how much ram would your OS “see”?

    • Tony says:

      In that configuration, the OS wouldn’t boot. You’d need to use a 64-bit OS.

      • Wayne says:

        I find the whole memory thing confusing. Basically i had 4 gigs ram. Vista would show approx 3.26 available. Now my graphics card was Nvidia 8800m GTX 512 mb ram plus a second sli one. So if the graphics card mapping should steal 512 mb ram only why did it drop as far as 3.26 gig only being available. Or another way of looking at it, is if they were in Sli confg then surely my available should of been more like 3.072 and not 3.26. Why is this?

        Funnily enough I had to do a factory restore on my dell laptop which returned it to it’s factory shipped state. Suddenly the available memory changed to 3.072? Why did it suddenly do this? Maybe the fact the bios was upgraded to a newer version is responsible?

        Another oddity – my 8800m GTX slis were eventually replaced due to overheating by dell. In their place are 9800m GTX cards in sli. Each with 1024 mb memory. So surely my available vista memory should now read 4096 – 1024 – 1024 equalling 2.048. Yet it still says 3.072. It’s bizarre. Anyone know why this happens?


        • Heya Wayne. It’s not just the video card that steals address space, so the remaining .24 GB must be allocated by a bus (such as the PCI bus) or another card. The video card just happens to be the biggest culprit.

          I’m not at all sure why updating the BIOS would change the available memory. Maybe the new BIOS update mapped more address space to some system component.

          Re: the two cards in SLI, I’m not an expert in SLI, but based on what you’re saying, it sounds like the two cards are addressed by a single address space. I think SLI just shares processing, right?

  67. Wim Bervoets says:

    If you can’t find your bios update at the manufacturer site, a good place to start is http://www.wimsbios.com/biosupdates.jsp. You should be able to find a bios update via the manufacturer links.


  68. Wayne says:

    Hi Tony

    Many thanks for your response. I am inclined to agree with you that maybe the BIOS update mapped more address space to a system component. I do have an ageia physx card in the laptop (now redundant as 9800 gtx has an onboard chip) so I guess this takes some of the addressing.

    As for the SLI, I guess the 2 cards are addressed by a single space and share the processing. I don’t truly understand how it works. I suppose 2* 1024 mb cards would be a a bit draconian if they took all that address space leaving me with just over 2 gig available!

  69. Bob says:

    Create a RAMdisk (using something like RAMDisk Plus. Make sure it’s only using un-used RAM)
    Then go into virtual memory settings (Vista: Control Panel>Performance Information and Tools>Advanced Tools>Adjust the Appearance and Performance of Windows, advanced tab, change…)
    Set virtual memory paging file to run on your newly made RAMDisk.

    This is what I did. I’m not really sure if it helped, as my computer was runnung top notch before hand, anyway.

    I hope I’ve been a help.

    • Unfortunately, this would just waste memory. Windows has a really complex algorithm for deciding what should be stored in physical vs. virtual memory, and tricking it like this will only reduce performance.

      • Bob says:

        After doing some research I found that I was also suppose to go into regedit and change it to clear the page file at shutdown.

        To be honest I’m not really sure if there has been much of a performance change (in my case). I could still play Fallout New Vegas (with maxed graphics), and watch a movie on my secondary monitor, whilst runnung a myriad of programs in the background, and still have it all run flawlessly. In the end I’m not really sure if it did help any, but I didn’t really notice any increase or decrease in performance.

        I’ll likely give my extra RAM away, as I didn’t really notice a performance differance.

        Thanks for the input.

  70. Matt Peters says:

    I am running 32-bit Vista on my laptop with 2GB (2x1GB) RAM. Does it make any sense to upgrade to 4GB (2x2GB) or can I just replace 1 SoDIMM and live with 3GB.