4GB RAM in 32bit OS

[iceangel89]

what will happen when i have 4GB RAM in a 32bit OS like Windows XP Pro or Vista?

like in http://members.cox.net/slatteryt/RAM.html?

the RAM will be allocated to other things like:

* System ROM

* APIC(s)

* Integrated PCI devices, such as network connectors and SCSI controllers

* PCI cards

* Graphics card

* PCI Express cards (if applicable)

automatically?

how can i verify this? since my Graphics card has Turbo Cache, i intend to allocate the extra to this can i?

[cluberti]

Yes, automatically. Please search the forums before posting sometimes, too - this has already been extensively covered and documented here and elsewhere. And stickied .

[puntoMX]

how can i verify this? since my Graphics card has Turbo Cache, i intend to allocate the extra to this can i?

That also depends on your motherboard BIOS settings as you already could read, and the Turbo-cache will only take the memory when it needs it, e.g. with more/larger textures for example in games. With the Gigabyte motherboards and any VGA card it will show 3.5GB in Windows XP/Vista 32bit, I didn´t test it with extra PCI/PCI-E cards like RAID controllers and so.

[nitroshift]

[...]With the Gigabyte motherboards and any VGA card it will show 3.5GB in Windows XP/Vista 32bit, I didn´t test it with extra PCI/PCI-E cards like RAID controllers and so.

On my machine I had 3582MB of RAM shown in Computer Properties (the DVB satellite card was and still is identified in Device Manager as a network controller). That was when I was running the 32-bit version of Vista and had only 4GB of RAM, now I see the whole amount of 8GB

Edited March 11, 2008 by nitroshift

[puntoMX]

On my machine I had 3582MB of RAM shown in Computer Properties...

So it’s 2MB less then 3.5GB, what a rip-off .

I didn’t know that Vista can clear the other 0.5GB, never worried about it any way as I’m using 64bit version of Vista/ Debian (9a) any way .

[TravisO]

The "official" explanation from a infamous MS employee on the matter, if you really want to know all the nerdy details of where that last 500mb goes:

http://blogs.msdn.com/oldnewthing/archive/.../14/699521.aspx

[nmX.Memnoch]

With.......any VGA card it will show 3.5GB in Windows XP/Vista 32bit

This actually depends on how much RAM is on the video card. If it's 256MB the system will show ~3.75GB, 512MB it'll show ~3.5GB and with a 768MB card it'll show ~3.25GB. The attached screenshot is from my work system, which has a 768MB Quadro FX 4600.

[UtCollector]

Hmms, i got 4 gb installed now. First only 2. Because i wanted my pc to use dual channal i installled a nother 2 gb of the same memory. (Insted of adding the last gb of supported memory) Everyting works just normal. In windows properties it say's 3,25 gb installed.

Some motherboards suport up to 8 gb installed.. I sure hope future os will support more memory.

[cluberti]

Hmms, i got 4 gb installed now. First only 2. Because i wanted my pc to use dual channal i installled a nother 2 gb of the same memory. (Insted of adding the last gb of supported memory) Everyting works just normal. In windows properties it say's 3,25 gb installed.

Some motherboards suport up to 8 gb installed.. I sure hope future os will support more memory.

XP / 2003 x64 and Vista x64 support terabytes of memory. 32bit can only address memory space at 2^32, or 4096. It's an architectural limitation, one which only a 64bit OS can address.

[puntoMX]

This actually depends on how much RAM is on the video card. If it's 256MB the system will show ~3.75GB, 512MB it'll show ~3.5GB and with a 768MB card it'll show ~3.25GB. The attached screenshot is from my work system, which has a 768MB Quadro FX 4600.

Showoff (points at 768MB Quadro FX 4600).

Any way, I have to admit that I don’t have any 768MB or 1GB video cards around here, so I tested it with some, without turbo cache or that crap, 256MB and 512MB video cards and it still shows 3.5GB... How about that? o.O

[jcarle]

No offence, but this thread should have been locked with a reference to one of the thousands of threads discussing this issue. This has been discussed to death and then some.

Edited March 16, 2008 by jcarle