4 GB in laptop but only 3,230.18 MB showing

[Blake Mengotto]

Is this normal?

 

[Andre Da Costa[ActiveWin]]

The system memory that is reported in the System Information dialog box in
Windows Vista is less than you expect if 4 GB of RAM is installed:

http://support.microsoft.com/kb/929605/en-us

Understanding Address Spaces and the 4GB Limit - [H]ard|Forum:
http://www.hardforum.com/showthread.php?t=1035670

 

[Meinolf Weber]

Hello Blake,

In 32bit OS, yes.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups

 

[David Sanders]

Is this normal?

Yes. You will never see the full 4GB because in 32-bit systems
everything has to be accessible within 4GB of address space. So some of
your ram won't be used because the kernel will map those addresses to
video cards or other hardware.

 

[Blake Mengotto]

So Vista 32 bit will only see 3 GB and be able to use 3 GB? I thought if
you had more memory, even if windows could not use it, other applications
that are memory intensive could.. I guess this is wrong and I can only
access this memory if I upgrade to the 64bit version. Is this a correct
assumption?

 

[David Sanders]

So Vista 32 bit will only see 3 GB and be able to use 3 GB? I thought
if you had more memory, even if windows could not use it, other
applications that are memory intensive could.. I guess this is wrong and
I can only access this memory if I upgrade to the 64bit version. Is
this a correct assumption?

Yes, if you want to use all of your memory, install a 64-bit OS.

 

[Dustin Harper]

True. Any 32 Bit OS can only use 4 GB of addressable memory. Even with 4 GB
of RAM, you still have the BIOS, video RAM, and other devices mapped to that
addressable memory. And Windows can only use what is left over, this
includes applications. The 64 bit version is the way to access that other
memory.

Vista 23 Bit SP1 will correctly tell you how much RAM is installed, but not
how much Windows can use.

 

[Blake Mengotto]

Ok, well that's cool, as long as it is being used..right? I may not see it,
but it's being used I hope. I thought all 32 bit platforms were limited to
max 4gb of ram.

I guess I get a bit confused with workstation operating systems, because
server (w2k3) based you can install 8 gb of mem or more and let apps like
Exchange and SQL use the additional memory with switches enabled in the boot
files. However the OS (W2K3) will only be able to address the first 4 GB of
mem. Or am I wrong about this as well..

 

[jorgen]

So Vista 32 bit will only see 3 GB and be able to use 3 GB? I thought
if you had more memory, even if windows could not use it, other
applications that are memory intensive could.. I guess this is wrong and
I can only access this memory if I upgrade to the 64bit version. Is
this a correct assumption?

Yes, you need an address space larger than 4 GB to hold everything. And
Microsoft doesn't want to support than in their non-server editions

 

[Blake Mengotto]

Ok cool. So I didn't waste my money upgrading from 2gb to 4gb.. Thanks guys!

 

[David Sanders]

Vista 23 Bit SP1 will correctly tell you how much RAM is installed, but
not how much Windows can use.

Vista 23 bit?

 

[Dustin Harper]

Yea, I got the Vista 23 bit SP1. Its a discounted version of Vista.
Microsoft removed 9 bits so it's easier for my dyslexic fingers to screw up
and it fixes it. Got it for $00.98. Or something like that.

 

[Dustin Harper]

The RAM isn't being fully used. Only ~3.2 GB of it is. The other ~800MB is
there, just can't be used. That 800MB of address space is being used for
video RAM, I/O, BIOS, etc.. Everything that needs memory needs to be mapped
in that address space.

A 64 bit OS will allow a lot more RAM to be used, as it's address space is
much larger. So, the video RAM and other I/O information can be mapped,
still leaving plenty of space for your RAM. So, all 4 GB (or more) of RAM
can be used and seen by Windows.

 

[jorgen]

True. Any 32 Bit OS can only use 4 GB of addressable memory.

It is actually a decision made by Microsoft to NOT support more than 4
GB address space. They whine a bit about bad drivers

 

[David Sanders]

Yea, I got the Vista 23 bit SP1. Its a discounted version of Vista.
Microsoft removed 9 bits so it's easier for my dyslexic fingers to screw
up and it fixes it. Got it for $00.98. Or something like that.

Vista 23-bit would be limited to using 2^23 (8MB) of RAM.

 

[Dustin Harper]

Actually, this is incorrect. 32 Bits = 4 GB of address space. It's a
limitation in the mathematics, not Microsoft. You can enable PAE, which I
think extends it to 36 GB. It's not bound to the OS, it's bound to the 32
bit architecture. The OS can tell you how much physical RAM you have (even 8
GB on a 32 bit machine), but it can only access < 4 GB.

"By definition, a 32-bit processor uses 32 bits to refer to the location of
each byte of memory. 2^32 = 4.2 billion, which means a memory address that's
32 bits long can only refer to 4.2 billion unique locations (i.e. 4 GB). "

 

[Dustin Harper]

Here is a good article (along with the /pae switch) where I obtained that
quote. Also, there are many others, so this information is correct.

http://www.brianmadden.com/content/article/The-4GB-Windows-Memory-Limit-What-does-it-really-mean-

 

[Dustin Harper]

Yea. But Vista SCREAMS on this 386 I'm running. I got a great deal on it,
too. No math coprocessor.

 

[jorgen]

Actually, this is incorrect. 32 Bits = 4 GB of address space. It's a
limitation in the mathematics, not Microsoft. You can enable PAE, which
I think extends it to 36 GB. It's not bound to the OS, it's bound to the
32 bit architecture. The OS can tell you how much physical RAM you have
(even 8 GB on a 32 bit machine), but it can only access < 4 GB.

And PAE is the mode Vista runs in by default.

 

[Dustin Harper]

No, it's not:

http://msdn2.microsoft.com/en-us/library/aa906211.aspx

"On 32-bit versions of Windows, PAE is disabled by default."