4GB limit or 3GB?

[Guest]

Howdy,

I have Ultimate with 4GB of ram in my Lenovo ThinkPad T61p. The hardware
supports 4GB and I already called Lenovo about this issue. They say it's a
Windows limitation. From what I read on Microsoft's site though, Vista can
support 4GB. I started searching around and found many people saying its
supported and many saying it doesn't support 4GB but i haven't found a fix
anywhere. Anyone know how to get this to recognize 4GB?

Thanks,
David Lozzi

 

[Carey Frisch [MVP]]

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

Why doesn't my Windows PC recognize the whole 4GB of memory I installed?
http://www.crucial.com/kb/answer.aspx?qid=4251

--
Carey Frisch
Microsoft MVP
Windows Shell/User

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

:

Howdy,

I have Ultimate with 4GB of ram in my Lenovo ThinkPad T61p. The hardware
supports 4GB and I already called Lenovo about this issue. They say it's a
Windows limitation. From what I read on Microsoft's site though, Vista can
support 4GB. I started searching around and found many people saying its
supported and many saying it doesn't support 4GB but i haven't found a fix
anywhere. Anyone know how to get this to recognize 4GB?

Thanks,
David Lozzi

 

[Andrew McLaren]

I have Ultimate with 4GB of ram in my Lenovo ThinkPad T61p. The hardware
supports 4GB and I already called Lenovo about this issue. They say it's a
Windows limitation. From what I read on Microsoft's site though, Vista can
support 4GB. I started searching around and found many people saying its
supported and many saying it doesn't support 4GB but i haven't found a fix
anywhere. Anyone know how to get this to recognize 4GB?

Hi David,

Are you running 32-bit or 64-bit Vista?

If you're running 32-bit Vista, it will not "see" more than around 3GB of
RAM. This is a well-known limitation; see:
http://support.microsoft.com/default.aspx/kb/929605

32-bit Windows Vista can indeed use a full 4GB of virtual address space.
But, some of that 4GB address space is needed for the physical hardware,
such as the video card. Typically, around 1GB is used up by hardware
addresses. So that leaves 4GB minus1GB (=3GB) for random access memory: RAM.

There's a handy diagram explaining the concept, here:
http://www.codinghorror.com/blog/archives/000811.html

64-bit Vista has a much larger address space. If you run 64 bit Vista, you
*might* be able to see the full 4GB, if (and only if) the chipset supports
at least 8GB of RAM and the BIOS supports the memory remapping feature. I
wouldn't recommend moving to 64-bit Vista just to use the extra 1GB of RAM,
though - unless the hardware really supports it, just installing 64 bit
Vista won't necessarily make the full 4GB available; and there are many
potential compatibility problems you would need to consider. Unless you have
specific applications which require a larger address space (typically,
high-end CAD or engineering applications, large databases, etc, not desktop
apps) then you're better off just leaving the 1GB RAM unused.

I don't want to point the finger too hard at Lenovo, but ... it's not in
their interest to sell you a machine with *less* RAM. It's easier and more
profitable for them to sell machines with 4GB RAM ready-installed and then
say, "Oh naughty Microsoft; crappy Vista can't see the full 4GB". A computer
engineer would have known, from day one, that no 32-bit OS would use the
full 4GB of RAM (you would encounter similar problems with 32-bit Solaris,
Linux, or any other x86 operating system). Or maybe the memory architecture
issue is a bit subtle, and their front-line support guys just haven't worked
it out yet. Don't be scared to push them for a better explanation.

Hope it helps,

 

[Xenomorph]

You need a 64-bit version of Windows if you wish to use 4 Gigs of RAM or
more.

 

[Guest]

I purchased the RAM seperately, cheaper that way.

So, if I was to downgrade to 3GB of ram, would I drop to 2GB in the
software??

 

[AJR]

No. Address space is used not RAM - Installing 3 gigs of RAM leaves 1 gig
of address space for the system.

 

[Guest]

OK, and I just confirmed it. I now have 3 gigs of ram.

Thanks to all

 

[Translator French - English - Creole]

my apologies but answer isn't really clear for me it's seems you are saying
both answers, so "no" he wouldn't have two gig after installing three gig,
but the part that gets me confused is the end where you say that the system
takes or the ram leave 1 gig for address space, where does it take it from?
if you don't mind explain it more throughly,

changing subject: it's funny that even a geek like me who's been around pc
since i was 5 years old(when they had 386 processors, then 486) would be
asking to get something explained to him. well, it must be because i'm a
geek and love to know it all, he he he he.

--
New Boating Capt. Jonathan Perreault

Personnal Advice To You:
#1: Do Not Undermine Windows's Work, Or It'll Undermine You As A User.
#2: Torture Windows (Any) Now Before It Tortures You
#3: Windows Is Bad Enough In English, Why Get It In Another Language

Best Comments From Users:
No Matter The Problem Even With Linux, It's Microsoft's And Windows's Faults

A common mistake that people make when trying to design something completely
foolproof is to underestimate the ingenuity of complete fools.

 

[Translator French - English - Creole]

if i were you i would stick with 4 gb since you have it, i'm sure it helps
the pc in some way, but your choice.

--
New Boating Capt. Jonathan Perreault

Personnal Advice To You:
#1: Do Not Undermine Windows's Work, Or It'll Undermine You As A User.
#2: Torture Windows (Any) Now Before It Tortures You
#3: Windows Is Bad Enough In English, Why Get It In Another Language

Best Comments From Users:
No Matter The Problem Even With Linux, It's Microsoft's And Windows's Faults

A common mistake that people make when trying to design something completely
foolproof is to underestimate the ingenuity of complete fools.

 

[jorgen]

my apologies but answer isn't really clear for me it's seems you are
saying both answers, so "no" he wouldn't have two gig after installing
three gig, but the part that gets me confused is the end where you say
that the system takes or the ram leave 1 gig for address space, where
does it take it from? if you don't mind explain it more throughly,

You have a magic bag filled with memory addresses, 4GB total. They must
be distributed among all the hardware devices. RAM usually gets about
3GB of them.

So you can install up to 3GB usable RAM. Anything above, wont get an
address (that 32-bit xp/vista can see), and is of no use.

 

[jorgen]

if i were you i would stick with 4 gb since you have it, i'm sure it
helps the pc in some way, but your choice.

With 3x1GB vs 4x1GB the difference is single vs dual channel

 

[Dave]

I have 3 GB in vista Home Premium 32... it shows 3 GB.

 

[Meinolf Weber]

Hello David,

You have to install the 64bit version to get the full 4GB. The 32bit version
can not address the full 4GB, this is by design since 32bit operating systems
start. So it is not a bug that you can fix.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.

 

[jorgen]

Hello David,

You have to install the 64bit version to get the full 4GB. The 32bit
version can not address the full 4GB, this is by design since 32bit
operating systems start. So it is not a bug that you can fix.

If Microsoft wanted, they could release a PAE kernel that can address
more than 4GB, and leave the problems with bad drivers to the user

 

[DevilsPGD]

If Microsoft wanted, they could release a PAE kernel that can address
more than 4GB, and leave the problems with bad drivers to the user

Unfortunately it doesn't work like that -- All the complaints here about
3GB would turn into "Vista claims it can handle 4GB but when I put in
4GB, Vista crashes, MS sucks"

 

[Guest]

It also depends on other factors. For example, I bought a Dell XPS 710 with
Vista Ultimate, a Quad Core Processor, 4GB RAM, and a 768MB video card.
After spending all this $$, you can imagine my frustration when I saw that
Vista only showed 3.2GB of RAM installed. After scouring various Dell and
Microsoft newsgroups, I found the problem was my Video Card. Vista sees this
768MB as system RAM and subtracts this from the 4GB of RAM
installed....leaving me with 3.2GB available. Check out this Microsoft Link
- it's all here:

http://support.microsoft.com/default.aspx/kb/929605