4Gb RAM issue?

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The_Unbeliever

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Hi there

We got a set up at work with 4Gb RAM. The motherboard sees 4Gb, but WindowsXP only sees 3Gb.

Limitation of Windows, or do I need to jiggle some bits? :D

Cheers!

Libs
 
Windows XP limitation. Should see about 3.4-3.6Gb.
I have same issue on home pc.
Linux should see everything :)
 
You could always install XP 64-bit, if you're feeling adventurous. Not really worth the effort though, in my humble opinion.
Edit - that's assuming Vista is out of the question
 
The_Librarian said:
Hi there

We got a set up at work with 4Gb RAM. The motherboard sees 4Gb, but WindowsXP only sees 3Gb.

Limitation of Windows, or do I need to jiggle some bits? :D

Cheers!

Libs
Click to expand...

More like a 32bit os limitation. Some people only have their windows see 3gigs.
 
32bit os can not use all 4GB. In range of 3.2-3.5, 64bit does not have this limit.
 
Windows 32bit can only address 4GB of memory in total, including memory on display cards etc. That is why can't see the whole 4GB RAM, and it shows up as 3.X.

Edit: PAE will not help, the limit is still 4GB shared amongst all resources.....
 
Conradl said:
Windows 32bit can only address 4GB of memory in total, including memory on display cards etc. That is why can't see the whole 4GB RAM, and it shows up as 3.X.

Edit: PAE will not help, the limit is still 4GB shared amongst all resources.....
Click to expand...

+1.
 
Conradl said:
Windows 32bit can only address 4GB of memory in total, including memory on display cards etc. That is why can't see the whole 4GB RAM, and it shows up as 3.X.

Edit: PAE will not help, the limit is still 4GB shared amongst all resources.....
Click to expand...

Technically incorrect.
Read the link dracolusus gave.
I have a 32-bit Windows 2003 Enterprise Server accessing and using 12 GB of RAM.
It's XP and Vista that don't have the correct PAE support for more than 4GB. Windows 7 too, for that matter.
 
When should we make the switch to 64Bit Operating Systems?
 
Correct me if i'm wrong but wasn't one of the limitations of a 32bit architecture that it has only a 4GB addressable memory range limit? Regardless of the OS involved... In fact, I seem to remember someone's marketing campaign for 64 bit architecture involving this line somewhere...

The limitation of 4GB is a hardware limitation, and although the OS maybe impose its own limitations, the issue at its core remains hardware and not software related.

I have a 32-bit Windows 2003 Enterprise Server accessing and using 12 GB of RAM.
It's XP and Vista that don't have the correct PAE support for more than 4GB. Windows 7 too, for that matter.
Click to expand...

Yep, and I'm guessing you running a 64bit architecture... :)
 
Last edited:
Linoman said:
32bit os can not use all 4GB. In range of 3.2-3.5, 64bit does not have this limit.
Click to expand...

Well it'll be 4Gb subtract the memory on your graphics card as a 32-bit OS can only address 4Gb memory in total...
 
The_Librarian said:
Interestingly, that Linux also give the same issue.


:(
Click to expand...

Remember that manufacturers also impose limits on the amount of addressable memory - for example, how many laptops have you seen advertised that say "1GB of RAM upgradable to 2GB" and not upgradeble to a full 4GB of memory? Granted, this mainly applies to older hardware and these days they don't seem to impose this anymore, but well, there you have blatant manufacturing limitations...
 
timgaul said:
Well it'll be 4Gb subtract the memory on your graphics card as a 32-bit OS can only address 4Gb memory in total...
Click to expand...

Hmmm, but is the graphics memory addressable by anything in the system, or is it dedicated graphics memory (only addressable by the Graphic card processor)?

Sounds like a stupid question, but applying logic tells you that dedicated graphic memory is invisible to the main system as it is only addressable by the GPU. There is no link between it and the main memory and it cannot be accessed via anything but the GPU... in other words, not counting toward that 4GB addressable memory limit of the main system.

Granted this changes if the graphic memory is shared...
 
masticore said:
Technically incorrect.
Read the link dracolusus gave.
I have a 32-bit Windows 2003 Enterprise Server accessing and using 12 GB of RAM.
It's XP and Vista that don't have the correct PAE support for more than 4GB. Windows 7 too, for that matter.
Click to expand...

Not technically incorrect.
2^32=4096MB RAM. PAE uses page tables to increase the addressable memory by 4 bits to 36. Thus 2^36 = 64GB. 32bit can only see 4GB max....

following your logic you'll have an 800Mb graphics card, if you can only see 3.2Gb...?
Click to expand...
Yes, and if you had 1GB cards in SLA then you would have less then 2GB.... Also it has nothing to do with whether the memory is shared or not....
 
Last edited:
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