Vista RC2 x86 PAE not working. Only sees 3 of 4GB memory

[Peter Meinl]

32bit Vista RC2 only sees 3 of 4GB memory installed on my Intel D975XBX
mainboard.
Vista RC2 x64 sees all 4GB, so this seems not to be a mainboard problem.
The boad documentation says it supports memory remapping, there is no bios
setting to turn it on or off.

Will this be fixed with the final Version?

 

[ML]

Unlikely. This is due to the limit of the 32-bit OS architecture......

 

[Guest]

It was my understanding Vista Ultimate should recognize up to 8GB of memory
without the PAE switch.

Please advice

 

[ML]

You need to be running x64 version of ultimate.....

 

[Peter Meinl]

32bit Vista Ultimate should definitely support 4GB+ RAM.
According to this article even more than 16GB:
http://www.winsupersite.com/showcase/winvista_editions.asp

 

[ML]

And you believe this guy Paul who has been wrong on a lot of the stuff about
vista?
Here is from Microsoft MSDN.

http://msdn.microsoft.com/library/d...y/base/memory_limits_for_windows_releases.asp

 

[Peter Meinl]

@ML: Thanks for the MS link, I searched for one myself to back up what Paul
wrote but did not find anything.

The following MS article contradicts the other one:
http://msdn.microsoft.com/library/d..._17b4305e-23ac-40ea-99db-4858b29a5d66.xml.asp

In case someone wonders what I want the memory for: it is for concurrently
running vitual OS.

 

[ML]

Well. For the running virtual OS, I would go for VMWare Server (free) on
64-bit OS....... VPC2007 still leaves a lot to be desired and seems to be
years BEHIND VMWare.........

 

[Guest]

Since it is similar to XP then, shouldn't you use the /3gb/PAE switch?

 

[Peter Meinl]

I am trying to use 64bit Vista (that is what I wanted to do from the
beginning on) and experimenting to find the right vitualization SW.
But I have problems with 64bit drivers not being available or not being
signed (see my other post today on Okt. 25)

 

[Guest]

@ ML, that is crap.... Just came from beta2 with an in place upgrade to rc1.
Beta2 can see all 4GB and RC1 can only see 3454MB. It is a MS problem...
/PAE is and was used as a workaround for the 32 bit limitation. I have built
enough w2k3 servers (32 bit) to know 4GB is not a problem. W2k 32-bit (ent)
with /pae also manages greater than 4Gb.

There is something significantly different with RC1 and RC2 (32-bit) from
beta2 that does not auto-magically enable PAE support. Most likely this
workaround was turned off by MS themselve due to stablility issues.

JM

 

[Peter Meinl]

I opened a service request with Microsoft (SRZ061127002189) to get a
definitive answer.

Here a summary of their answer:
32bit Vista does by design not(!) use the full 4GB of physically installed
RAM.
Technically it could use 4GB (by using PAE to access the memory remapped by
the mainboard above the 4GB address boundary). By a marketing design
decision all Windows Vista 32bit editions are limited to 4GB address space.
Vista Starter ist limited to 1GB. "This is based on marketing decisions and
cannot be cheated with the PAE-Kernel."

I find it hard to believe that someone made such a marketing decision: I can
understand that MS limits physical memory of some Vista edtitions to 4GB. I
do not understand a design decision to not fully use this memory even though
it is technically possible. I assume there are technical or security issues
involved - but this is just my feeling and not based on facts.

Some background links:

Intel® Chipset 4 GB SystemMemory Support
http://www.polywell.com/us/support/faq/4GB_Rev1.pdf

Memory Limits for Windows Releases
http://msdn.microsoft.com/library/d...en-us/memory/base/memory_limits_for_windows_r
eleases.asp

Information regarding PAE-Kernel:
http://msdn2.microsoft.com/en-us/library/ms791485.aspx
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx