Can WinXP (x86) see more than 2GB of ram, or not?

  • Thread starter Thread starter mjs
  • Start date Start date
Carl Kaufmann wrote:

> mjs wrote:
>
>> "Tim Slattery" <Slattery_T@bls.gov> wrote in message
>> news:9261i3h8kudvvuajj842qdg308ng2i4k2f@4ax.com...
>>
>>> It will not be able to use all 4GB of your RAM. See
>>> http://members.cox.net/slatteryt/RAM.html
>>
>>
>> But will it be able to use more than 2GB?
>>
>> Seems everyone here is comparing apples with oranges. On one side,
>> people are saying I WILL be able to use more than 2GB of ram. On the
>> other, they're saying I WON'T be able to use all 4GB.
>
>
> 32-bit Windows will be able to use (4 GiB - whatever is needed for
> hardware addressing). An individual application gets to use up to 2
> GiB. There are exceptions to this, but I'm not fully versed on the
> details and hence will keep my mouth shut.

You are confusing Virtual Address Space with RAM, the two are not the
same at all.

John
 
"John John" <audetweld@nbnet.nb.ca> wrote in message
news:OMbV5pxFIHA.3672@TK2MSFTNGP02.phx.gbl...
>
> What is it that you did not understand in the other replies in your
> thread? Windows XP can only address (supply addresses) for 4GB of
> memory. Memory does not mean RAM only, it means memory for everything in
> the computer. Practically all the devices need memory addresses, if you
> have 4gb of RAM in the machine and if the video card has 512MB you need to
> supply addresses for 4.5GB or memory, but XP can only address 4GB, so it
> will supply the addresses to the video card and that will reduce the
> available addresses for RAM to 3.5GB, it has to cut the addresses
> somewhere and the only place it can cut without crippling devices is by
> cutting available addresses for the RAM.
>
> We don't know what the memory requirements for your devices are, but we do
> know that they will receive addresses before the RAM and that means that
> YOU WILL NOT BE ABLE TO USE ALL 4GB OF RAM. Based on common knowledge and
> rules of thumb all we can say that you will not be able to use the last
> 500 to 1250MB of RAM in the machine. If you want to know the approximate
> exact amount look in the Device Manager and show resources by connection.
> Get yourself a hexadecimal converter and figure out the memory resources
> for the devices and subtract it from 4GB and you will know approximately
> how much of your RAM will be usable.
>
> John

I apologize if I'm being a bit too direct here, but I keep reading this over
and over again and what it seems to boil down to is something that can be
summed up a lot more simply than the pages and pages of replies in this
thread describe : "The amount of RAM used is however many you have installed
minus whatever your graphic card is using."

That's the bottom line, isn't it? In practice, if not in theory. Then why
not just say THAT? I mean, everyone keeps talking about "other things" that
could be getting into that ram space, but the BIOS is insignificant in
size -- as is just about everything else with the possible exception of the
video card.

I've said time and time again what my hardware is. Why is it so hard to
concede that in this very specific scenario, I'd have A LOT to gain by
installing 4GB of ram?

The applications NEED the ram. The video card is a mere 128mb model. What
other factors exist to scare me out of installing more than 2GB of ram? From
all accounts, it's a no-brainer in the OP's (my) situation : INSTALL 4GB OF
RAM.

Or am I STILL missing something in this debate?
 
mjs wrote:
> "Tim Slattery" <Slattery_T@bls.gov> wrote in message
> news:9261i3h8kudvvuajj842qdg308ng2i4k2f@4ax.com...
>> It will not be able to use all 4GB of your RAM. See
>> http://members.cox.net/slatteryt/RAM.html
>
> But will it be able to use more than 2GB?
>
> Seems everyone here is comparing apples with oranges. On one side, people
> are saying I WILL be able to use more than 2GB of ram. On the other, they're
> saying I WON'T be able to use all 4GB.
>
> Something tells me the truth lies somewhere in-between. That BOTH sides are
> right. That I will never be able to use 4GB of ram on WinXP x86, but that I
> can probably see and use 3GB -- especially if I'm only running a single
> 128mb 6600GT video card (Asus EN6600GT, to be more precise).
>
> The apps I use make high use of ram, where even the slightest increase in
> performance will be a huge relief. So if adding 2 more sticks of ram (4GB
> total) will allow me to use only 3.5GB, then I will add 2 more GB. Yes, that
> half-GB is something I'm willing to pay $50 for.
>
> If, on the other hand, my limit is more likely to be 3GB, then I will buy a
> single stick and add it.
>
> What I HAVEN'T seen in these exchanges is anyone inferring that 2GB is my
> limit. It seems that at the very LEAST, I could add a 3rd stick. Right?
>
> The question now becomes... do I add a 4th?
>
>
I currently have 3 GB of RAM installed in my computer, 2 x 512 MB and 2
x 1GB, and have times where XP has allocated over 2.5 GB of it. I
normally have around 1.5 GB of memory committed.
 
"mjs" <no@thanks.com> wrote in message
news:uRLWx8pFIHA.280@TK2MSFTNGP03.phx.gbl...
>I am running WinXP Pro SP2 on an Asus A8N-SLI Deluxe motherboard (AMD64).
>
> I've been thinking of upgrading my RAM to 4GB (from 2GB) but I keep
> hearing conflicting stories about WinXP's ability (or lack of it) to
> recognize all of it when running at 32 bits.
>
> I'd like to get the truth straight from the horse's mouth - if I add 2
> more sticks of ram in there (4GB total), will my system be able to see all
> 4 GB?
>
> Yes or no?
>
> Let's put this debate to rest once and for all.
>
It has already been put to bed numerous times.
Jim
 
"mjs" <no@thanks.com> wrote:

>"Tim Slattery" <Slattery_T@bls.gov> wrote in message
>news:9261i3h8kudvvuajj842qdg308ng2i4k2f@4ax.com...
>>
>> It will not be able to use all 4GB of your RAM. See
>> http://members.cox.net/slatteryt/RAM.html
>
>But will it be able to use more than 2GB?

Yes. It will use as much as it can allocate addresses to.

>Seems everyone here is comparing apples with oranges. On one side, people
>are saying I WILL be able to use more than 2GB of ram. On the other, they're
>saying I WON'T be able to use all 4GB.

There may be confusion between physical RAM and the 4GB virtual
address space given to each process. The virtual space is normally
divided half-and-half between the OS and the process. the /3GB switch
confines the OS to 1GB, leaving 3GB virtual memory for the app. That
constrains the OS, and should be done only in rare cases. /3GB will
have NO effect on physical RAM.

Physical RAM, at any time, will have pieces of *many* virtual address
spaces in it. One of the most important things the OS does is to keep
track of this, and figure out what to write to the swap file when a
process needs to allocate more space or read a page from the swap
file.

--
Tim Slattery
MS MVP(DTS)
Slattery_T@bls.gov
http://members.cox.net/slatteryt
 
mjs wrote:

> I apologize if I'm being a bit too direct here, but I keep reading this over
> and over again and what it seems to boil down to is something that can be
> summed up a lot more simply than the pages and pages of replies in this
> thread describe : "The amount of RAM used is however many you have installed
> minus whatever your graphic card is using."

Well sure, that is the biggest part of where the lost memory addressing
goes. But then when users come here and tell us that they have no video
card but still cannot use or "see" all the 4GB of RAM aren't you going
to have to explain all of this over again. Won't you have to tell them
about on board video and that their sound card might be using 64MB or
more? And then of course you will still have to explain to some users
why it is that a video card with it's own independent memory can be
"stealing" memory from the RAM. Many will be hard pressed to understand
why they even bothered to buy that expensive video card with 768MB of on
board memory.

John
 
mjs wrote:

> "John John" <audetweld@nbnet.nb.ca> wrote in message
> news:OMbV5pxFIHA.3672@TK2MSFTNGP02.phx.gbl...
>
>>What is it that you did not understand in the other replies in your
>>thread? Windows XP can only address (supply addresses) for 4GB of
>>memory. Memory does not mean RAM only, it means memory for everything in
>>the computer. Practically all the devices need memory addresses, if you
>>have 4gb of RAM in the machine and if the video card has 512MB you need to
>>supply addresses for 4.5GB or memory, but XP can only address 4GB, so it
>>will supply the addresses to the video card and that will reduce the
>>available addresses for RAM to 3.5GB, it has to cut the addresses
>>somewhere and the only place it can cut without crippling devices is by
>>cutting available addresses for the RAM.
>>
>>We don't know what the memory requirements for your devices are, but we do
>>know that they will receive addresses before the RAM and that means that
>>YOU WILL NOT BE ABLE TO USE ALL 4GB OF RAM. Based on common knowledge and
>>rules of thumb all we can say that you will not be able to use the last
>>500 to 1250MB of RAM in the machine. If you want to know the approximate
>>exact amount look in the Device Manager and show resources by connection.
>>Get yourself a hexadecimal converter and figure out the memory resources
>>for the devices and subtract it from 4GB and you will know approximately
>>how much of your RAM will be usable.
>>
>>John
>
>
> I apologize if I'm being a bit too direct here, but I keep reading this over
> and over again and what it seems to boil down to is something that can be
> summed up a lot more simply than the pages and pages of replies in this
> thread describe : "The amount of RAM used is however many you have installed
> minus whatever your graphic card is using."
>
> That's the bottom line, isn't it? In practice, if not in theory. Then why
> not just say THAT? I mean, everyone keeps talking about "other things" that
> could be getting into that ram space, but the BIOS is insignificant in
> size -- as is just about everything else with the possible exception of the
> video card.
>
> I've said time and time again what my hardware is. Why is it so hard to
> concede that in this very specific scenario, I'd have A LOT to gain by
> installing 4GB of ram?
>
> The applications NEED the ram. The video card is a mere 128mb model. What
> other factors exist to scare me out of installing more than 2GB of ram? From
> all accounts, it's a no-brainer in the OP's (my) situation : INSTALL 4GB OF
> RAM.
>
> Or am I STILL missing something in this debate?
>
>

Not much as far as a debate. Install 2 more GB of RAM, and accept what
increase you actually get. Simple as that.
 
mjs wrote:

>
> Or am I STILL missing something in this debate?
>
>

If you want proof, read the back pages of this doc ("experimental data").
It contains real numbers collected from a real system, using WinXP 32 bit.
See Table 2, rightmost three columns, 4GB RAM installed, a little more
than 3GB available.

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

Paul
 
Bob I wrote:

> Not much as far as a debate. Install 2 more GB of RAM, and accept what
> increase you actually get. Simple as that.

Amen!

John
 
You can second that Amen!!

JS

"John John" <audetweld@nbnet.nb.ca> wrote in message
news:eYw%231DzFIHA.1204@TK2MSFTNGP03.phx.gbl...
> Bob I wrote:
>
>> Not much as far as a debate. Install 2 more GB of RAM, and accept what
>> increase you actually get. Simple as that.
>
> Amen!
>
> John
>
 

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