I know that in both Windows XP & VISTA (any version) 32bit versions
We can't install & use more than about 3 Gigs of RAM .
The O/S uses some addresses above 3 Gig for addressing the hardware..
particularly the Graphic card ..
My question is how can I tell how much is available to use in a particular
system ??
Some people get 3.3 gig some nearly all of the 4 Gig space.

I've seen a spec. for a Dell system that has 2 SLI Geforce 8800GTX &
4 gigs RAM fitted that gives the available RAM amount as only 2.7 Gig.
An extreme example. That's because the 8800's both have 768MB memory
that has to be mapped in the upper memory.

I want to know how much I will get if I install more RAM or some
piece of hardware's effect in this respect.
Mouse
@@@

So do I. I called Gigabyte about this, and the tech said
that Windows will only report unmapped ram .. therefore
the 3 gig .. 3.3gig .. etc ... BUT .. he said that the system
will still use your 4 gigs of ram. I can only assume that
the video card ram is not on the memory bus, but is treated
like I/O .. and maybe even like a serial device. Otherwise,
the video ram addressing would conflict with the system
memory addressing. Main reason I think this, is the term
"ram" doesn't make any sense for a video card. There is
no need to "randomly" access the ram on a video card.
That clearly makes it some kind of serial device .. like
a UART ... that can be tri-stated and share its bus. If
there is some kind of random logic on a video card,
it has its own internal bus for that, and so there is no
system "memory addressing" going on. It would be
nice to find out the facts one way or the other. I'm
using 4 gigs of ram, and it makes a big difference in
Vista and G3.

johns

On 7 Mar, 19:58, "Trimble Bracegirdle" <no-s... (AT) Spam (DOT) Not> wrote:
You know about Physical Address Extension (PAE), a method of accessing
up to 64GB of memory on a 32-bit processor?

http://www.microsoft.com/whdc/system...AE/PAEdrv.mspx

(\__/)
(='.'=)
(")_(")
Hi Johns
Much nicer type of person here than on those "ibm. com. games" groups, yes ?

I'm putting new sys together & as will be using 32 bit O/S because of
the computability & driver issues Re: 64 bit.
I just decided & ordered an extra 1 Gig of RAM for 3 Gig total.
Fills up all the slots of cause in dual channel.
I would have gone to 4 Gig if not for this uncertainty..
I don't understand the info. you've been given that Windows
use all of 4 Gigs but may show less ???
Mouse
(\__/)
(='.'=)
(")_(") Bunnies must rule.

(\__/)
(='.'=)
(")_(") Thanks for the PAE link...But its mostly over my head..
Seeems to come down to "maybe , maybe not" ..after a lot of work
It would be usefull just to have some utility to run & tell what adding
more RAM would do.
Mouse
(\__/)
(='.'=)
(")_(")

"Trimble Bracegirdle" <no-spam (AT) Spam (DOT) Not> wrote

Vista has a performance and reliability program built in. Part of that is a
Windows Experience Index, which is a numerical rating that is like a GPA for
how well your system is prepared to run Vista. Your number is based on the
WEAKEST component. That is, if your CPU scores a 2 (that's bad), then your
baseline score is 2, even if all your other components are 5 or better. My
wife's computer got a 5.8 base number out of a possible 5.9. It has exactly
2GB of RAM.

The question is not how much RAM can you get, it's how much extra RAM can I
add before I start wasting money? It seems Vista is happy with 2GB. Stop
there. -Dave

That would be Gothic 3. I swear I'm not kidding
when I call myself a "benchmark gamer". These
games are telling me a whole lot more than all
the Microsoft FAQ sheets in the world added
together. Something like Aquamark is pretty
good. It just hangs a number on game efficiency.
I can spend weeks calling AutoDesk, or Gigabyte,
or Microsoft .. and learn nothing. I can load a
couple of games and right away, I can see for
myself where the problem areas are ... and
see if anything fixes those problems. The game
writers have no reason to lie about their products,
and I go to the Engineering vendors armed with
the truth ... and catch them in lie after lie after
lie ... mostly that I am too stupid to run their
products. So I ask which "shader" they are
using ... and it will be so out-of-date, it is not
funny. I drop back in their app, and all is
well. Nice to know these things.

johns

You see anywhere in that baseline that Vista does
not support OpenGL, and its XP dll library is 2 years
out of date. And then there's the weasel-wording at
the bottom of the page, that many pieces of hardware
may not work as expected ??? Microsoft jargon style
says one thing, and means the exact opposite ...
reminds me of my Physics professors.

johns

You see anywhere in that baseline that Vista does
not support OpenGL, and its XP dll library is 2 years
out of date. And then there's the weasel-wording at
the bottom of the page, that many pieces of hardware
may not work as expected ??? Microsoft jargon style
says one thing, and means the exact opposite ...
reminds me of my Physics professors.

johns

Trimble Bracegirdle wrote:
Try PDF page 51 here and Figure 3-1 "System Address Ranges". This
is for the P965 chipset.

ftp://download.intel.com/design/chip...s/31305302.pdf

Chipsets that support more than 4GB of memory, such as the P965,
have a remapping function. It allows the memory whose addressing
was used by the I/O devices, like PCI/AGP/PCI-Express cards, to be
recovered by remapping to above 4GB. But that only helps, if you
have a 64 bit OS that can access up there. Remapping for a 32 bit OS
won't help, because while the wasted memory is lifted up, it cannot
be accessed. So expect to install 4GB and get to see and use 3.3GB
or whatever the number turns out to be. If you use an SLI or Crossfire
setup, expect the "address space tax" to be higher, than if you just
put an old PCI video card in the computer.

The address map efficiency is all a function of the BIOS, and also
of the "rules of rounding". Space allocation for some of the I/O,
is sometimes rounded to the nearest 256MB and the like. Which means,
if you just stepped over one of those boundaries, you lose a chunk more
of RAM from addressability.

This doc is originally from Intel, and is available for download from
Asus. It provides a bit more background info.

http://dlsvr01.asus.com/pub/ASUS/mb/4GB_Rev1.pdf

There are also limitations at the OS level. The kernel application
split can be 2GB/2GB or 1GB/3GB. To be able to use 3GB for a single
application, may require specifically compiling the application for it.
If more than one application is running, then the sum total of their
memory usages, comes from the application space.

And discussions of this topic always end in a "food fight", so I'll
put on my rubber raincoat and cover my head now :-)

Paul