RAM question

  • Thread starter Thread starter Ed\(NY\)
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Ed\(NY\)

I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G, or
8.2G even though it doesn't recognize it?

(2) If not, when is a SP supposed to come out that will rectify that?

Thanks-
 
After installing SP1, Vista will correctly report
the amount of "installed RAM", but unless you
are running the 64-bit version of Vista, the
conventional 32-bit version of Vista will only
use what it's capable of using. Please see:

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

Windows Vista SP1 will report 4 GB of system memory (RAM) on
systems that have 4 GB of memory installed:
http://support.microsoft.com/kb/946003/

--
Carey Frisch
Microsoft MVP
Windows Shell/User

---------------------------------------------------------------

:

I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G, or
8.2G even though it doesn't recognize it?

(2) If not, when is a SP supposed to come out that will rectify that?

Thanks-
 
Ed(NY) said:
I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G, or
8.2G even though it doesn't recognize it?
Click to expand...

Vista 32-bit will only use about 3GB of RAM. Vista 64-bit supports:

Windows Vista Edition 64-bit memory support

Home Basic 8 GB
Home Premium 16 GB
Ultimate 128+ GB
Business 128+ GB
Enterprise 128+ GB

-Chris
 
I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram
Click to expand...


No, not correct.

All 32-bit versions of Windows (not just Vista) have a 4GB address
space. That's the theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you 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.

Note that the hardware is using the address *space*, not the actual
RAM itself. The rest of the RAM goes unused because there is no
address space to map it too.

This is a problem only in 32-bit Windows The 64-bit versions don't
have this limitation.

- will it utilize 4.1G, or
8.2G even though it doesn't recognize it?
Click to expand...



No and no. It can't use what it can't see.

(2) If not, when is a SP supposed to come out that will rectify that?
Click to expand...


Never. There's nothing to rectify. This is not a software bug, but a
built-in limitation of the hardware architecture.
 
Ed(NY) said:
I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G,
or 8.2G even though it doesn't recognize it?
Click to expand...

Depends, do you have 32 bit or 64 bit?

32 bit will never go more than 4GB of RAM, not possible. At that, the PC
has to swap out memory and will only ever be able to see/use about 3.1GB of
it if 32 bits.

If 64 bits, it will see all the memory the current PCs can hold.
(2) If not, when is a SP supposed to come out that will rectify that?
Click to expand...

SP anything will not change this. 64 bits if you want to see much more than
3.1GB.
 
I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G,
or 8.2G even though it doesn't recognize it?

(2) If not, when is a SP supposed to come out that will rectify that?

Thanks-
Click to expand...

The 32 bit version does not have the ability to utilize more than 4gb in
any way, shape or fashion. There are apparently no plans to change that.
If you need to utilize that much, suggest you switch to Linux - 32 bit
version accomodates up to 64gb.
 
No, not correct.

All 32-bit versions of Windows (not just Vista) have a 4GB address
space. That's the theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you have
a 4GB address space, you 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.

Note that the hardware is using the address *space*, not the actual RAM
itself. The rest of the RAM goes unused because there is no address
space to map it too.

This is a problem only in 32-bit Windows The 64-bit versions don't have
this limitation.





No and no. It can't use what it can't see.




Never. There's nothing to rectify. This is not a software bug, but a
built-in limitation of the hardware architecture.
Click to expand...

Not quite. 32 bit versions of Linux support up to 64gb.
 
32-bit Vista is limited to addressing 4 gig or ram. It shows the portion
available to the operating system, approx 3.5gig. I understand that while
nothing changes but the display of the amount of ram, that it will now show
total ram after SP1, but someone else will have to confirm.
 
1. No.

2. Never.

This is a limitation of 32-bit operating systems, not "Vista".
 
Ed\(NY\) said:
I have two questions I hope someone can answer:

(1) I believe Vista only recognizes 3.5G of ram - will it utilize 4.1G, or
8.2G even though it doesn't recognize it?
Click to expand...

No, of course not. See http://members.cox.net/slatteryt/RAM.html
(2) If not, when is a SP supposed to come out that will rectify that?
Click to expand...

The problem is in the 32-bit hardware, so there's no software fix
possible. 64-bit Vista will support much more RAM.
 
ray said:
Not quite. 32 bit versions of Linux support up to 64gb.
Click to expand...

Use PAE, I'd guess. MS server operating systems support PAE in this
mode, desktop systems (like Vista) don't.
 
Desktop systems (like Windows 2000 and XP prior to SP2) do also. But
they remain 32 bit OSes, with all the 32 bit limitations.

The problem is that there are drivers (nVidia for example) that don't
work well with the PAE hack and crash the OS, so MS wisely decided to
eliminate the issue from Vista (and XP SP2) by not doing the PAE hack
any longer. It isn't needed anyways, now that we have real 64 bit
hardware and OSes. It is/was a short-term solution whose time has
passed.
Click to expand...

I don't consider utilizing your hardware to be a 'hack'.
 
The fact that Vista only "sees" 3.5GB of ram is a hardware limitation,
and has nothing to do with the operating system. No amount of service
packs will correct that.
Click to expand...

Depends on how you use 'operating system'. The 3.3GB you refer to is the
amount of ram available to the os and it's programs after allocating that
necessary for peripherals.
Even my old computer, Vista Ultimate x64 on had 3.3GB available, even
though I had 4GB ram installed. My new machine (that I build only today)
reported the full 4GB as available, even before Vista SP1 was installed.
Click to expand...

Your new machine has set by default to remap the peripheral to higher
addressable memory.
 
dzomlija said:
The fact that Vista only "sees" 3.5GB of ram is a hardware limitation,
and has nothing to do with the operating system. No amount of service
packs will correct that.

Even my old computer, Vista Ultimate x64 on had 3.3GB available, even
though I had 4GB ram installed. My new machine (that I build only today)
reported the full 4GB as available, even before Vista SP1 was installed.
Click to expand...

The 3.1 or 3.5GB limitation you hear of is a COMBINATION of operating system
and hardware.

You get the LOWER of the two. If your motherboard has 8GB, and you are
using 32 bit, 32 bit and memory remapping in Vista 32 bit will limit you to
3.1 to 3.5GB.

If your motherboard only holds 2GB of RAM, does not mater be it Vista 32 bit
or 64 bit, all you will ever see is 2GB.

You need to have both the operating system and the hardware to operate above
the 2 and 3.1 GB limits.
 
dzomlija said:
Even my old computer, Vista Ultimate x64 on had 3.3GB available, even
though I had 4GB ram installed. My new machine (that I build only today)
reported the full 4GB as available, even before Vista SP1 was installed.
Click to expand...

Once again, even though Vista now reports all 4GB, it still cannot use
all of it.
 
PAE itself is a hack. It tacks an additional 4 bits onto what is
otherwise 32 bit hardware and OS. So you get 36 bits of address space
(64 GB) on an otherwise 32 bit system. So when you load the special 36
bit kernal you can have 64 GB of physical RAM but still no process can
allocate more than 2 GB virtual RAM because it's still a 32 bit OS.
Unless you recompile your app specifically for it (think EEMS and page
frames). IOW, it's a kludge - a hack.

Now that true 64 bit hardware and OSes are here, we no longer need 32
bits + 4 extra hacked on bits.
Click to expand...

What exactly do you mean "now that true 64 bit hardware and OSes are
here"? I was using Tru64 Unix on a DEC Alpha 10 years ago!!
 
Bob Campbell said:
The old computer running Vista 64 must not have had the BIOS option to remap
memory.
Click to expand...

You're right, he does say he's running 64-bit Vista. I wonder what
happened, in that case, to show 3.3GB even though he had 4GB
installed? Maybe it shares RAM with the video system, so even though
there's 4GB installed it sees 3.3GB as system RAM and the other .7 as
video RAM. Sounds odd to me.
 
Most BIOS's don't automatically remap the memory hole. You would have to
set it manually.
 
We're talking commercially available computers here, not niche machines
like the DEC Alpha...
Click to expand...

OK - 64 bit Linux systems have been available since shortly after
"commercially available" 64 bit processors appeared - it was MS, as
usual, who lagged.
 
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