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jmFightSpam

macrumors regular
Original poster
Aug 24, 2007
115
0
Hi,

I have seen on some threads here and other forums that Windows Vista can only use/show about 3.5 GB of available RAM. I just installed 4 GB on my MacBook Pro, and when I right click on "Computer" the System stats show "3054 MB" RAM. So mine is only showing 3.0 GB RAM. Should I be concerned that it is not even showing 3.5 GB RAM?

Thanks.
 

Jeremy1026

macrumors 68020
Nov 3, 2007
2,215
1,029
Hi,

I have seen on some threads here and other forums that Windows Vista can only use/show about 3.5 GB of available RAM. I just installed 4 GB on my MacBook Pro, and when I right click on "Computer" the System stats show "3054 MB" RAM. So mine is only showing 3.0 GB RAM. Should I be concerned that it is not even showing 3.5 GB RAM?

Thanks.

Do you have 64-bit or 32-bit Vista. Only 64-bit Vista can pick up 3.5GB, 32-bit Vista and XP can only recognize 3.0GB
 

jmFightSpam

macrumors regular
Original poster
Aug 24, 2007
115
0
Do you have 64-bit or 32-bit Vista. Only 64-bit Vista can pick up 3.5GB, 32-bit Vista and XP can only recognize 3.0GB

AHh...I have 32-bit. I guess I misunderstood. I thought 32-bit could pick up the 3.5 GB.

On a similar note, I heard that Vista SP1 is going to be able to at least recognzie 4 GB, albeit it cannot use all of it. I wonder if that is true.
 

LOZER

macrumors member
Jan 12, 2008
70
0
Kalamazoo, MI
AHh...I have 32-bit. I guess I misunderstood. I thought 32-bit could pick up the 3.5 GB.

On a similar note, I heard that Vista SP1 is going to be able to at least recognzie 4 GB, albeit it cannot use all of it. I wonder if that is true.

At least you've got that much i have 5Gb's in my Mac Pro and Vista only recognizes 2Gb's, but thats more than enough for what I need.
 

contoursvt

macrumors 6502a
Jul 22, 2005
832
0
Vista64 and XP64 will show your full RAM. 32bit windows might show as little as 2.5GB or as much as 3.5GB depending on what cards are installed and how much VRAM is on the video boards..etc. Your 3GB is pretty standard for a 32bit windows.
 

irishgrizzly

macrumors 65816
May 15, 2006
1,461
2
I've heard that windows doesn't make as good use of RAM that macs do. So this isn't such an issue, right?
 

contoursvt

macrumors 6502a
Jul 22, 2005
832
0
Actually windows doesnt have much of an issue with memory management (its quite good). The problem is the way the 32bit support is implemented in XP and Vista. Windows server 32bit versions can address more than 4GB as well. Its just the desktop versions that have this limitation.

If you go with the 64bit versions, then there is no issues. I have 8GB right now in my Vista64 box and its all good.
 

contoursvt

macrumors 6502a
Jul 22, 2005
832
0
Thats true but thats a hardware limitation. Obviously if you cannot put more than 4GB RAM, you wont get more than 4GB RAM in Vista64 or XP64 or OSX.

Now if the system can only accept up to 4GB RAM physically but is capable of 64bit processing, then you will get your entire 4GB in 64bit operating systems. I have an old Xeon box here for example that has 4GB RAM (thats all it can take) but I only get 3GB available to me when running XP 32bit. If I install Vista64, I will get 4GB.

Basically a 32bit OS normally can see up to 4GB max of address space. PCI cards, video cards and other devices need to reside within this 4GB space or else they will not be available. So a computer with 4GB RAM running XP32 will have issues because other hardware are overlapping the RAM. Thats why sometimes adding PCI cards in XP and Vista 32 bit systems cause a RAM reduction.



Doesn't it depend on the chipset used as well, some chipsets only support up to 4 Gig?
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
yeah

video card for instance has memory too so that brings it down a bit. I have 4 gigs also and get 3gigs usable in vista 32-bit
 

jbg232

macrumors 65816
Oct 15, 2007
1,148
10
Sorry to revive an old post, but better than creating a new one right? And my question involves this topic:

I'm really confused over which components of the computer determine how much RAM vista will see. I know 32-bit supports 4GB theoretically and that is divided in two for the programs and the os and that 64-bit supports 128 gb. But it doesn't make sense to me how more hardware components = less RAM recognizable to Vista?

More importantly for my needs - what will a macbook with 4gb RAM look like to vista 32-bit?
 
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