XP pro not seeing all 4gb

[Vertigo0176]

I just installed 4gb of 800mhz dual channel ram on my ASUS PB5 Deluxe MB, CPUZ sees all 4GB but Windows only sees 3GB. I though XP pro can see 4GB max?

 

[Idontcare]

ZOMG! That is teh uber suck!

Did you google to see if anyone else on planet earth has discovered this? You might be the first, and that means you get to name it!

I humbly suggest calling it the "Vertigo176 32-bit O2 never sees 4GB of ram memory debacle".

 

[Vertigo0176]

Thanks

 

[ryderOCZ]

On a serious note.

Vista and XP 32-bit will not show all 4GB in Windows, only the 64-bit variants will. Look for memory remap and enable it in bios, this will get the bios to display all 4GB anyway.

 

[Idontcare]

On a serious note, Google is your friend.

31,000 hits in Google search for the OP's EXACT topic title

 

[Quiksilver]

Someone should sticky a thread explaining this issue (although if people actually bothered to search google or the forums they would already know the answer) as it seems we get one of these threads every other week or so.

 

[MegaVovaN]

No need for sticky nobody reads them. Stickies are like banners: they are infront of your eyes but you trained yourself to be blind to them.

 

[Hurricane Andrew]

Originally posted by: ryderOCZ
On a serious note.

Vista and XP 32-bit will not show all 4GB in Windows, only the 64-bit variants will. Look for memory remap and enable it in bios, this will get the bios to display all 4GB anyway.

Actually, Vista SP1 will show all RAM installed, even on 32-bit installs. It just won't use it.

 

[Tarrant64]

Originally posted by: Hurricane Andrew

Originally posted by: ryderOCZ
On a serious note.

Vista and XP 32-bit will not show all 4GB in Windows, only the 64-bit variants will. Look for memory remap and enable it in bios, this will get the bios to display all 4GB anyway.

Actually, Vista SP1 will show all RAM installed, even on 32-bit installs. It just won't use it.

Link?

 

[pallejr]

Originally posted by: Tarrant64
Link?

http://technet2.microsoft.com/...a03e1033.mspx?mfr=true

 

[Tarrant64]

Originally posted by: pallejr

Originally posted by: Tarrant64
Link?

http://technet2.microsoft.com/...a03e1033.mspx?mfr=true

Thanks.

 

[Oric]

This means RAM prices will fall

 

[Tarrant64]

Originally posted by: Oric
This means RAM prices will fall

No?

RAM prices already dropped awhile ago.

 

[Martimus]

32 bit operating systems can only use 4GB of memory. It is a limitation with 32 bit (2^32 = 4,294,967,296 memory addresses). You will never be able to use more that 4GB of memory on a 32bit operating system, so to fix this you would need to go to 64 bit (2^64 = 18,446,744,073,709,551,616 memory addresses). This includes video memory on Vista.

A better explanation of what is going on and what you can do about it is given here in three parts:
http://www.anandtech.com/gadgets/showdoc.aspx?i=3034
http://www.anandtech.com/cpuch...ts/showdoc.aspx?i=3044
http://www.anandtech.com/systems/showdoc.aspx?i=3060
It is interesting, and does show some tricks to get more of that 4GB available to your applications, but it won't be possible to use more than 4GB until you move to a 64 bit operating system.

 

[Nothinman]

32 bit operating systems can only use 4GB of memory. It is a limitation with 32 bit (2^32 = 4,294,967,296 memory addresses). You will never be able to use more that 4GB of memory on a 32bit operating system, so to fix this you would need to go to 64 bit (2^64 = 18,446,744,073,709,551,616 memory addresses). This includes video memory on Vista.

Ever heard of PAE? With it a 32-bit OS can use 36-bit addressing letting the OS use up to 64G of physical memory. Each 32-bit process will still be limited to 4G of virtual address space but there are various methods to work around that, i.e. AWE.

 

[pallejr]

It is also worth noticing that both xp and vista has a pae kernel, and load it by default to have support for dep. So if Microsoft wanted to support >4G it wouldn't take much

 

[Nothinman]

It is also worth noticing that both xp and vista has a pae kernel, and load it by default to have support for dep. So if Microsoft wanted to support >4G it wouldn't take much

It wouldn't take much at all, but MS still decided to not allow access to any address >4G in the non-server editions of 32-bit Windows so even with PAE enabled all you really get is DEP.