Vista DRAM size

[Guest]

I install 4MB dram 11 in my system my CMOS reports that 4Mb of ram is
installed, when i open windows vista it only registers 3MB i have swithced
and tested the banks they all work, so does the individual chips. any
suggestions

 

[Guest]

You are running Vista 32 bit version. That is all the RAM it can use.
64 bit can use it all, as more memory addressing.

 

[Bistey Csaba]

You mean GB's i think. Think you are using 32bit Vista, if so here is a
brief description of 32bit addressing that will explain it.
http://www.codinghorror.com/blog/archives/000811.html

Csaba

Rulerguy wrote

 

[Kevin Weaver]

32 bit os will only see a total of 3.... If you want to see all 4 Install
the 64bit ver.

 

[Peter]

I guess I'm lucky...it shows 3.3gb in my Vista.

 

[Guest]

Thanks for reply

I guess I'm lucky...it shows 3.3gb in my Vista.

 

[Guest]

thanks

You mean GB's i think. Think you are using 32bit Vista, if so here is a
brief description of 32bit addressing that will explain it.
http://www.codinghorror.com/blog/archives/000811.html

Csaba

Rulerguy wrote

 

[Guest]

Thanks for reply

32 bit os will only see a total of 3.... If you want to see all 4 Install
the 64bit ver.

 

[Ken Blake, MVP]

I install 4MB dram 11 in my system my CMOS reports that 4Mb of ram is
installed, when i open windows vista it only registers 3MB i have swithced
and tested the banks they all work, so does the individual chips. any
suggestions

All 32-bit versions of Windows, even though they have a 4GB address
space, can only use *around* 3.1GB of RAM. That's because some of that
space is used by hardware and not available to the operating system
and applications. The amount you can use varies, depending on what
hardware you have installed, but is usually around 3.1GB. But I've
seen numbers as high as 3.5GB.

 

[Arend]

Hello guys,

I have 4 GB of memory (4096 MB) installed and it is being reported by
Windows Vista Ultimate as 3582 MB. If the claim that other hardware use some
of this memory how it comes that you get the correct value if you install
2048 MB?
And a 32-bit os can see up to 4096 of ram, or not?

Is there a hole somewhere or I just can’t see where my mistake in this
calculation is?

Regards,
Christos

 

[Ken Blake, MVP]

Hello guys,

I have 4 GB of memory (4096 MB) installed and it is being reported by
Windows Vista Ultimate as 3582 MB. If the claim that other hardware use some
of this memory

No, it uses some of the *address space*, not some of the memory. You
have roughly half a GB of address space that hardware is using and is
not available to map your RAM to. That last half a GB of RAM therefore
can not be used.

how it comes that you get the correct value if you install
2048 MB?

Because 3.5GB of address space *is* available to map your RAM to. 2GB
maps into the 3.5GB without a problem, leaving 1.5GB unmapped.

And a 32-bit os can see up to 4096 of ram, or not?

In theory. In practice it's subject to the limitation I explained.

 

[Rick Rogers]

Hi,

I have 4 GB of memory (4096 MB) installed and it is being reported by
Windows Vista Ultimate as 3582 MB. If the claim that other hardware use
some
of this memory how it comes that you get the correct value if you install
2048 MB?

The hardware is not using memory, it is using some of the 4GB of address
space available in a 32-bit operating system. There is 4GB of address space
by default. Some of this, depending on the hardware it might be anywhere
from .5GB to 1.3GB, is used by the system to address the components. The
remainder is given over to the physically installed ram. What you see
reported by Windows is the difference (4GB minus that reserved by the
system) whenever the amount of installed ram exceeds the number of addresses
available to allocate to it.

And a 32-bit os can see up to 4096 of ram, or not?

It can, but - and this is a big "but" - without remapping the system address
space above the 4GB mark (a BIOS setting), some of the available address
space will be used by it. What remains is allocated to system memory for
use. You get to see and use the difference in these figures. Remember, that
"theoretical" is not the same as "practical". You can theoretically use 4GB,
but in practice you really get between 2.7-3.3GB.

Is there a hole somewhere or I just can’t see where my mistake in this
calculation is?

The "hole" so to speak is that the original design of hardware address
allocation was placed at a level above what was ever concieved to be used by
physical memory. Some BIOS' have the option to reallocate around the memory
hole which will release more addresses for system memory. Whether or not
your system supports this remapping depends on the manufacturer.

--
Best of Luck,

Rick Rogers, aka "Nutcase" - Microsoft MVP

Windows help - www.rickrogers.org
My thoughts http://rick-mvp.blogspot.com

news:[email protected]...

 

[Mike Hall - MVP]

In addition to what Ken and Rick stated, you are lucky to see that much.
Some get less than 3gb seen.

You should not look at it as what you are losing, so much as what you are
gaining over 3gb..

 

[Arend]

Thank you guys!!!

I spent 400 euro, which is about 600 USD, for my ram (OCZ DDR2 - 1066) and I
freaked out when I saw Windows reporting lees than this! From the moment I
posted the comment I made a search about it in the internet and realized that
I must indeed be happy for seeing that much (3582 MB). However, your
explanations were the most comprehensive.

Regards from Athens
Christos