Max Memory in Win2K Limited to 2GB, Why?

[C. J. Clegg]

I have read in other articles in microsoft.public.* and elsewhere that
Windows 2000 should be able to access up to 4 GB of RAM, of which at
least 3 GB should be available to user programs.

I have been speaking with an acquaintance of mine whose company is
working on a system based on Windows 2000 on a Dell platform, and he
swears that they cannot get access to more than 2 GB of RAM with
Win2K.

(I asked why they aren't using WinXP and he said that the manufacturer
of one of the PCI-bus plug-in boards they use recommends against WinXP
because their drivers don't work well with it, or something close to
that ... but, I digress.)

Their application would benefit greatly by being able to access more
RAM, and I believe that they should be able to access at least 3 GB
with Win2K ... right?

Is there any reason why Win2K would have trouble accessing more than 2
GB, or is it more likely a hardware limitation (e.g. the motherboard
can't access more)?

Also, another question ... Can Win2K or WinXP take advantage of some
processors' (e.g. Pentium Pro) Page Address Extensions capability and
access up to 64 GB RAM?

 

[Adam Joseph Cook]

I have read in other articles in microsoft.public.* and elsewhere that
Windows 2000 should be able to access up to 4 GB of RAM, of which at
least 3 GB should be available to user programs.

I have been speaking with an acquaintance of mine whose company is
working on a system based on Windows 2000 on a Dell platform, and he
swears that they cannot get access to more than 2 GB of RAM with
Win2K.

(I asked why they aren't using WinXP and he said that the manufacturer
of one of the PCI-bus plug-in boards they use recommends against WinXP
because their drivers don't work well with it, or something close to
that ... but, I digress.)

Their application would benefit greatly by being able to access more
RAM, and I believe that they should be able to access at least 3 GB
with Win2K ... right?

Is there any reason why Win2K would have trouble accessing more than 2
GB, or is it more likely a hardware limitation (e.g. the motherboard
can't access more)?

Also, another question ... Can Win2K or WinXP take advantage of some
processors' (e.g. Pentium Pro) Page Address Extensions capability and
access up to 64 GB RAM?

Hey C.J.,

I have read in other articles in microsoft.public.* and elsewhere that
Windows 2000 should be able to access up to 4 GB of RAM, of which at
least 3 GB should be available to user programs.

I have been speaking with an acquaintance of mine whose company is
working on a system based on Windows 2000 on a Dell platform, and he
swears that they cannot get access to more than 2 GB of RAM with
Win2K.

(I asked why they aren't using WinXP and he said that the manufacturer
of one of the PCI-bus plug-in boards they use recommends against WinXP
because their drivers don't work well with it, or something close to
that ... but, I digress.)

Their application would benefit greatly by being able to access more
RAM, and I believe that they should be able to access at least 3 GB
with Win2K ... right?

Take a look at this article. I was having the same problems with my
CAD system until I read this. Notice the part about
IMAGE_FILE_LARGE_ADDRESS_AWARE.

http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

Also, another question ... Can Win2K or WinXP take advantage of some
processors' (e.g. Pentium Pro) Page Address Extensions capability and
access up to 64 GB RAM?

Here is another terrific article on this issue. I am going to assume
that Windows 2000 Pro can only address 4 GB of RAM per the Windows XP
specificiation.

http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx

I hope this helps.

--Adam Joseph Cook, Mechanical Engineer

 

[Dave Patrick]

Adam is correct and posted a couple of good links for you. The drivers that
come on the Windows installation media are supplied by the hardware
manufacturer's so there's no truth what-so-ever to the myth your
acquaintance proposes.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

:
|
| I have read in other articles in microsoft.public.* and elsewhere that
| Windows 2000 should be able to access up to 4 GB of RAM, of which at
| least 3 GB should be available to user programs.
|
| I have been speaking with an acquaintance of mine whose company is
| working on a system based on Windows 2000 on a Dell platform, and he
| swears that they cannot get access to more than 2 GB of RAM with
| Win2K.
|
| (I asked why they aren't using WinXP and he said that the manufacturer
| of one of the PCI-bus plug-in boards they use recommends against WinXP
| because their drivers don't work well with it, or something close to
| that ... but, I digress.)
|
| Their application would benefit greatly by being able to access more
| RAM, and I believe that they should be able to access at least 3 GB
| with Win2K ... right?
|
| Is there any reason why Win2K would have trouble accessing more than 2
| GB, or is it more likely a hardware limitation (e.g. the motherboard
| can't access more)?
|
| Also, another question ... Can Win2K or WinXP take advantage of some
| processors' (e.g. Pentium Pro) Page Address Extensions capability and
| access up to 64 GB RAM?

 

[C. J. Clegg]

Good morning, Adam.

Ah, OK, now we're getting somewhere.

From the information in the link provided above, the way I interpret
it is that only 2 GB of the 4 GB physical address space is available
to user programs ... UNLESS the /3GB switch is used ... AND the /3GB
switch is NOT available to Windows 2000 Pro (it's only available to
Windows 2000 Advanced Server and Datacenter Server among the Win2K
family).

So, it appears that in fact, user programs cannot use more than 2 GB
on Win2k Pro.

Do I interpret that correctly?

 

[Adam Joseph Cook]

Good morning, Adam.

Ah, OK, now we're getting somewhere.

From the information in the link provided above, the way I interpret
it is that only 2 GB of the 4 GB physical address space is available
to user programs ... UNLESS the /3GB switch is used ... AND the /3GB
switch is NOT available to Windows 2000 Pro (it's only available to
Windows 2000 Advanced Server and Datacenter Server among the Win2K
family).

So, it appears that in fact, user programs cannot use more than 2 GB
on Win2k Pro.

Do I interpret that correctly?

Hey C.J.,

Yeah, thats what I'm reading for Windows 2000 here. I would like to
see a MS MVP confirm this though.

Thanks.

--Adam Joseph Cook, Mechanical Engineer

 

[Bob I]

Hey C.J.,

Yeah, thats what I'm reading for Windows 2000 here. I would like to
see a MS MVP confirm this though.

Thanks.

--Adam Joseph Cook, Mechanical Engineer

Other confirming documentation

Available switch options for the Windows 2000 Boot.ini file
http://support.microsoft.com/kb/833722/en-us