4Gb of Memory with 32-bit Vista? Possible?

haha, just saw the thread below me. Is Vista any different than XP in this issue?

runswindows95 is incorrect. I am running a 32-bit OS and have full access to my 4 GB of memory:

Linux greed 2.6.20-16-server #2 SMP Fri Aug 31 01:01:45 UTC 2007 i686 GNU/Linux
total used free shared buffers cached
Mem: 4148616 3911308 237308 0 59204 3235500
-/+ buffers/cache: 616604 3532012
Swap: 2104472 1936 2102536

No, my intention was to point out that runswindows95 was incorrect when he stated that all 32-bit OS's max out at 3 GB. Windows XP SP2 maxes out around there as does Vista (32-bit). This is not a limitation fundamental to 32-bit OS's, though, and that was my only point. I'm sure other 32-bit operating systems also do not suffer from a 3 GB limitation.

In the Microsoft world, though, you'll need to go for a 64-bit OS.

hibye19013 is incorrect. Vista and Windows XP SP2 will limit you to around 3 GB of RAM in their 32-bit flavours. You may be able to access a little more or a little less but it'll be around 3 GB.

I am using a fairly bog-standard Gigabyte K8NXP-SLI motherboard. I have 4 GB of RAM and I can use 4148616K of that. Granted, that's a little over 45 megs under the 4GB limit but don't forget that the operating system needs some of that space, etc. etc.

Still, 45 megs is really just a rounding error when you are talking about 4 GB. And given that this 45 megs is actually in use anyway (by the operating system), I think it is fair to say that I am able to use my 4 GB.

Right now, I'm using 3784784 K of my 4 GB.

Zenmaster is correct about PAE. I believe their 32-bit consumer OS's were limited to around 3 GB, though, because they couldn't fix the driver issues.

I'm not sure that running a server version of Windows is a reasonable alternative for home users, particularly for gamers. I think you are better off going with the 64-bit version of Vista and just accepting that this is not a great option at the moment either. Still, if you have only 4 GB, you may be better served by going with a 32-bit Windows OS and just accepting that you are throwing away 1 GB or so of your RAM. It's certainly the option with the least hassle.

Anyway, Vista 64 is an awesome system. I would recommend to anybody installing a new OS to go 64. I forgot what a BSOD is, and I'm a heavy gamer. The only issue with the 64bit Vista is the driver signature thing, and there are workarounds for that. Even Rivatuner is signed now.

If you have a retail version of Windows Vista and you got only the 32bit version, you could ask Microsoft to ship the 64bit version to you for under $10.

>> Anyway, Vista 64 is an awesome system.

Uhh no it REALLY isn't. I'm running it right now and its total crap compared to XP. It uses nearly half of my 2GB of ram even without any apps running. Everything runs much slower under vista than XP and since downgrading from XP to vista I can't play my own DVD's any more as vista whines about DRM paths.

Vista also uses 11GB of disk space compared to 2GB for XP, and it seems to be doing all sorts of network traffic that I haven't asked it to do, so god knows what Microsoft is up to. Ans before anyone suggests, No I don't have a virus.

If it wasn't for lack of DX10 support I'd go back to XP in a heartbeat.

@ niz: I think you need to compare XP when it was relatively new to Vista 64. Not the current SP2 with fixes and updates to a virgin Vista 64.

I only say this because XP sucked when it was new, and I am running XP32 and Vista64 ultimate and vista is faster...in only the programs I have installed on it (office 07, photoshop, etc.) I know there are limitations but it is a new OS so give it time.

P.S. I am not a windows fan boy.

Well, Vista is not bad, but it's different than XP and you need to know what to expect.

1) It will take more resources to run. Vista 64 even more than Vista 32.
If your system is not up to snuff, it will not be the best way to go.

2) Vista 32 will have less support than XP for hardware software. Vista 64 even less. If you have older harderware and/or software it may not be the best option unless you dual boot.

3) Vista 64, with sufficient resources will be the future and provides more potential power then XP. Its the present for some but future for all.

NotherDude,

Read a little about PAE.
http://en.wikipedia.org/wiki/Physi [...] _Extension

You will clearly see that it's a complete fallacy that 32-Bit Operating Systems can only address 4gb of RAM.

No, it's not a Hack.
The "32-Bit" CPUs were physically changed years and years ago to allow for 36-Bit addressing and the "32-Bit" operating systems were also written to support the 36-Bit addressing.

The main "issue" with PAE is lack of testing by developers.
Probably many who even lacked systems to test with large amounts of RAM.

The issue still continues today with 64-bit code.
Here is a RANT about such things.
http://www.tomshardware.co.uk/Linu [...] 26094.html

OK, I'm open to this. But I read that Wiki article and it didn't really say that much about PAE to address the many disparaging things I have read about it.. From the article:

Are you saying that a whole new software mapping layer comes without a performance penalty or other problems? If not I would call it a hack. It certainly sounds at least like a 'way around' what is a fundamental limitation of the 32 bit OS to address more than 4 gig. No?. A bit like the old DOS situation.

Not to argue. I'm happy to admit I am really only repeating what I have heard and read and I'd be happy to stand down on this but I need more than that Wiki. This stuff is a little beyond my full understanding.

Could you link me to an authoritative source on this? I'm interested.

Some docs explaing page tables

http://technet2.microsoft.com/wind [...] 91033.mspx
http://www.amd.com/us-en/assets/co [...] erview.pdf
http://www.intel.com/design/proces [...] 253668.pdf

Hey all, good discussion. My situation is somewhat similar so rather than post a new thread I'll ask here.

I purchased some new RAM today, 4 gigs of the same type. After I installed it all, during POST it only showed me 3200mb. I found it odd, and tried to POST again with multiple RAM configurations to see if I had gotten a faulty stick. Satisfied that all the sticks were working but something else must be the issue I got online and started searching.

I now understand that I need to turn on (and have) the memory remaping feature in my BIOS. I also understand that in order to have access to 4gigs in Vista, I need to somehow (not really certain on this but haven't started looking yet either) enable PAE.

I have two major concerns before I proceed.

1) As has been stated (and from what I read on the MS knowledge base) PAE adds a new layer where it is basically translating 36bit to 32bit applications and vice versa. I'm sure this comes with a performance cost, but beyond that, my main issue is stability. Has this extra layer been known to cause stability issues? I find it difficult to believe that if Vista COULD truly support 4gigs natively, that it would not have been "on" by default.

2) If indeed I opt not to use PAE, should I turn my memory mapper back to the old setting? With memory mapper off I was showing 3200mb RAM, with it turned on, oddly enough I show about 3000mb. So if I decide PAE is not the option for me, do I gain any performance by keeping memory mapper on or should I turn it back off to regain my 200mb of RAM back (which incidently show up in Vista. I show up at 3200MB).

Thanks

As you may have seen from reading the above this issue gets rather complex, to my mind at least LOL

But PAE, as a switch you enable in Windows, is no longer an option for MS consumer level OS. (It might be for pre-service pack version of XP, according to some sources)

To use your full 4 gig you will need to get the 64 bit version of Vista (or XP).

The 'memory remapping' feature in the BIOS you are referring to is not the same thing as the PAE we were discussing (though it may be in some way similar in concept.) If you have a 64 bit OS you will need to turn on memory remapping in the BIOS to get your missing RAM. But you need a 64 bit OS in order to see it in Windows. If you don't have 64 bit it seems to turn off the extra gig you were otherwise getting in Windows, taking you from 3 down to 2, as happened to you and many others. You may see it in th BIOS but you don't in the OS. EDIT: I see for you it went from 3200 down to 3000, interesting, mine dropped from 3000 down to 2000 (approx) in Windows, although my BIOS reports 4. Perhaps you better list your specs here so someone can tell you if you meet the requirements.

To get the full 4 gig you will need;

1. 64 bit OS (on consumer level MS at least)
2. Motherboard that supports memory remapping (sounds like you have it)
3. 64 bit CPU (Athlon 64, or Intel core 2 duo generation)

That's the bottom line as I understand it.

Supposedly you can contact MS and they will send you the 64 bit version of your OS for a small fee. http://www.microsoft.com/windowsvi [...] fault.mspx

Thanks for the informative reply. I'm assuming a fresh install will be required and I simply can't do an upgrade to 64 bit?

Vista (32bit or 64bit) isn't setup to show all 4GB on all systems so they have a little hotpatch.

1) Start with 2GB, install the hotfix: http://support.microsoft.com/kb/929777

2) reboot to login with only 2gb installed.

3) Power down, install the last 2GB

4) Powerup.

You don't need to be getting the error mentioned in the hotfix to benefit from the patch, if your system already see's all 4 GB then there is no need but if you put in 4gb and see less than than you need the hotfix.

Vista does come with a pae kernel, which is why you can find references to it around the net.

The confusing part is, that even with pae enabled, it wont go above 4GB. It has pae to support hardware dep. pae is automatically enabled if you have a newer cpu (that supports the nx bit)

For ***** and giggles I enabled the PAE switch in my Vista 32 and the edit was sucessfully saved, but I still see 2.9 gig of RAM in system properties and if I enable memory remapping in BIOS I only get 2 gig in windows. Of course there may be more to it than simply enabling PAE?

I also see this from Microsoft:

I am confused. The article seems to indicate this is a fix for the problem but then clearly states you need a 64 bit OS to do it.

Can anyone explain all this is basic terms?

And if anyone is getting their full 4 gig in Vista 32 please raise your hand and post a screenshot.

It goes like this, to have support for all 4 GB you need:

* hardware that supports more than 4GB (address space), and memory remapping
* 64-bit Vista or XP
* 32-bit server Windows (with PAE enabled)
* 32 or 64 bit Linux

Nobody is getting the full 4 GB in Vista 32. Microsoft couldn't figure out how to get the drivers to work properly. You'll need Vista 64 to get the full 4 GB. Even then, there are other requirements such as your BIOS supporting memory remapping.

This limitation MAY not apply to the server versions of the Microsoft operating systems but you REALLY do not want to go that road. It certainly does not apply to Linux but again, no good to you if you are looking at playing the latest games, etc. etc.

When you enable pae in vista, you really get pae, the extra layer of address translation etc.

newer cpus supports something called the no executable bit, which can be used to indicate memory regions that cannot be allowed to hold executable programcode (virus, worms etc). To mark theses memory regions, you need to have pae enabled. Google DEP

When talking about so much memory, you also need to talk about the virtual address space that each application live in. This is fixed to 4GB in 32-bit, nomatter what you do. By default, applications can use 2GB of it for them selves.

In 64-bit this address space grows big...