Interesting read though it still stands that 32bit only addresses 4GB. The fact that
more could be mapped is true but 32bit apps would have to be written using AWE which
still limits linear address space to <4GB chunks. Biggest benefit of 64bit apps is
ability to use more than 4gb per app without the kludge.
As to the advantages for running multiple 32bit 4GB limited apps with > 4GB physical
RAM, should MS loosen the artificial limits of 32bit windows & PAE, that's how linux
seems to do it & how it should be in a perfect world.
This all quickly becomes moot since you get 32 & 64 on all new Vista/7 DVDs and 64
still let's you run your 32bit apps.
Soren wrote:
www.geoffchappell.com/notes/toc.htm ;)
maccrawj wrote:
2^32 IS 4GB, you do the math! ;)
From the MS page that lead me to the link I posted:
"Windows NT 4.0 Memory Support. With Microsoft Windows NT 4.0
Workstation and Server operating systems, the maximum amount of
physical memory supported is 4 GB. The maximum amount of virtual
memory is 2 GB.
With Windows NT 4.0 Server, Enterprise Edition, the /3GB switch was
first added to Boot.ini."
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx
AND
"The PAE mode kernel requires an Intel Architecture processor, Pentium
Pro or later, more than 4 GB of RAM, and Windows 2000, Windows XP, or
Windows Server 2003."
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx
Soren wrote:
Hey Brian,
As far as I know, the Windows NT generation is not limited to 3GB
RAM, only to 64GB (32bit O/S limit - do your own math ;). One thing
is what the O/S reports (and what MS wants us to believe), and
another thing is what's actually doable. Nothing new there,
unfortunately.
MS have several web pages describing the subject, though in very
cloudy terms. The essence is that WIN only reports up to 'about' +3GB
RAM, the rest is allocated to system (as in e.g. swap) and programmes.
The often overlooked fact is that WIN will only allocate up to 3GB of
RAM - per process, that is. How many processes are running on your
system?
I have build and/or setup several WIN NT systems with 4/8GB of RAM
w/o any problems at all. Those are all A/V systems with RAID and all
the bells and whistles, and no complaints so far. Oldest system is
almost eight years old.
It's kind of like the old NT-Switch-trick - only a few (like 2) keys
in the registry are changed, and then you've got Server. Bummer.
The limit for WIN NT Pro is 64GB by design (NT5/6/7/8=maybe). Home
Edition is limited to 32GB, for whatever reason. Probably "bragging
rights" :)
It's all on the MS web site, though in very cloudy terms. But the
determined individual will find it.
Using +4 GB will include the "/PAE" switch in boot ini. Normally,
this is added automatically by the O/S, and will run smoothly by so.
For an A/V system for professional use, 32GB RAM is not unusual on
e.g. WIN XP Pro.
HTH
