JW said:
KB...580 applies to a X86 system running Vista 32
KB...605 applies to 64 bit system running Vista 64bit
JW, are you sure? The "Applies To" section lists "Windows Vista ..." and
"Windows Vista ... 64-bit edition", and the article makes references to the
32-bit version. Either way, if ...580 applies to Vista 32-bit, then the
workaround would appear to have incomplete information, as I followed those
directions and am not getting 4 GB reported back.
Puppy Breath said:
LOL, I was scratching my head over that one too. By definition, a 32-bit CPU
can directly address up to 4GB of memory. But apparently nearly 1GB of that
is reserved for devices. So the most you can possibly see is 3.12GB in a
32-bit system. The way I read it, there is no way around it, no "fix" if
you're using a 32-bit version of Vista.
To see any more than 3.12 GB you have to be using a 64-bit version of Vista
plus meet all those other requirements (64-bit CPU instruction set, chipset
with 8GB address space, BIOS that supports memory remapping). That's the
way I read it anyway.
I think the DEP/ PAE thing is a whole different (but related) issue.
I think this is generally the case when not using PAE. Basically, there are
a fixed number of addresses that the system can send data to, specifically
2^32 (I'll leave the actual math to the reader). But, as I understand it
(which is by no means necessarily accurate), that's using the "standard"
addressing method. Enabling PAE changes the addressing method to use more
bits for the address to which the data is to be routed. From KB268363:
"With PAE enabled, the operating system moves from a two-level linear
address translation to a three-level address translation. The extra layer of
translation is what provides access to physical memory beyond 4 GB. Instead
of a linear address being split into three separate fields for indexing into
memory tables, it is split into four separate fields; a 2-bit field, two
9-bit fields, and a 12-bit field that corresponds to the page size
implemented by Intel Architecture (4 KB)." Granted, that KB article applies
to Windows 2000, but I imagine that the PAE implementation in Vista would be
similar, wouldn't it?
I kinda wish I had the hardware to see how this all plays out, because it is
really confusing. Do you use any of those little sidebar gadgets like
Multi-Meter that show how much RAM you're using? I'd be curious to know if
it shows something different than that System Info shows, and how far up the
scale you get with your software.
I do, but it only reports back the percentage of memory being used, not hard
numbers. If I had been smarter, I would've checked the info under Task
Manager before posting (from my laptop running XP). Of course, if I were
smarter maybe I would've figured all this out beforehand and not needed to
post!
Anyway, I appreciate the feedback and recognize that this topic is like the
cat from the popular song ("...but the cat came back / the very next day /
the cat came back / it wouldn't go away..."), but it appears to me anyway
that there is conflicting information even in Microsoft's knowledge base, and
I suspect that may be contributing to this subject's longevity and resiliency
to quashing. Can anyone else offer an explanation for the apparent
contradiction in the two articles (KB929580 and KB929605)? Links to those
articles can be found in previous posts. A link to KB268363 is included
below.
http://support.microsoft.com/kb/268363/en-us