Hi everybody.

SCENARIO:
Server with Windows x64 and 8 GB of physical ram;
some 64-Bit application running;
actual RAM usage 5 GB.

QUESTION:
If I add a (WOW64 compatible) 32bit application on this server, does it Work ?
I mean: is WOW64 able to give some memory space of Physical RAM between the
5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable memory
limitation of the majority of the 32 bit application but...it is not the
point of my question)
If yes I'll be greatfull for some documentation link about it.

Thank you in advance.

Pierluigi

Re: WOW64 and Actual Phisical RAM Usage by Tom

Tom
Fri Jun 08 10:34:11 CDT 2007

http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
http://msdn2.microsoft.com/en-us/library/aa366778.aspx
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64/wow64_implementation_details.asp
http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx

Tom
MSMVP
Windows Shell/User



"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
> Hi everybody.
>
> SCENARIO:
> Server with Windows x64 and 8 GB of physical ram;
> some 64-Bit application running;
> actual RAM usage 5 GB.
>
> QUESTION:
> If I add a (WOW64 compatible) 32bit application on this server, does
> it Work ?
> I mean: is WOW64 able to give some memory space of Physical RAM
> between the
> 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
> memory
> limitation of the majority of the 32 bit application but...it is not
> the
> point of my question)
> If yes I'll be greatfull for some documentation link about it.
>
> Thank you in advance.
>
> Pierluigi


Re: WOW64 and Actual Phisical RAM Usage by Pierluigi

Pierluigi
Fri Jun 08 10:53:02 CDT 2007

Hi Tom,
thank you very much for your replay.

I read these articles before, but they didn't answer my question.
I understand that my 32 bit application can take advantage of max 4 GB (in
very particular condition) of the "Virtual Address Space"
but I didn't understand if this "Virtaule Address" can be kept from every
physical address space in case I have more than 4 GB of Physical RAM.

"Tom Ferguson" wrote:

> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64/wow64_implementation_details.asp
> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>
> Tom
> MSMVP
> Windows Shell/User
>
>
>
> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
> > Hi everybody.
> >
> > SCENARIO:
> > Server with Windows x64 and 8 GB of physical ram;
> > some 64-Bit application running;
> > actual RAM usage 5 GB.
> >
> > QUESTION:
> > If I add a (WOW64 compatible) 32bit application on this server, does
> > it Work ?
> > I mean: is WOW64 able to give some memory space of Physical RAM
> > between the
> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
> > memory
> > limitation of the majority of the 32 bit application but...it is not
> > the
> > point of my question)
> > If yes I'll be greatfull for some documentation link about it.
> >
> > Thank you in advance.
> >
> > Pierluigi
>
>

Re: WOW64 and Actual Phisical RAM Usage by Charlie

Charlie
Fri Jun 08 19:47:49 CDT 2007

You have a mis-understanding of how memory addressing works and how that
relates to RAM. They are not the same thing. x64 Windows versions can use
>4GB of RAM (how much depends on the version), and all have an 8 TB
application memory address space.

The OS controls what applications are using what physical RAM. Regardless of
how much physical RAM you have, however, a 32-bit application has available
a 4 GB flat memory address space. If the application is written to take
advantage of all the memory available, it will see 4GB. If it is a
conventional 32-bit application, it will only see 2GB. 32-bit applications
have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
memory.

Now, if you load a 64-bit application that uses 5 GB of memory (notice I'm
NOT saying RAM here), and then want to load a 32-bit application that is
large memory aware, it will see 4GB of memory. If you then load another
32-bit application, it will see it's own 4 GB memory address space.

So, what does this have to do with RAM? Windows will decide what portions of
any of those applications are running in RAM, what portion of RAM it keeps
for itself, and what portion of any application it swaps out. This is the
job of the OS. The application doesn't use RAM, it uses memory. The OS
controls what memory is actually used for what purpose.

--
Charlie.
http://msmvps.com/xperts64
http://mvp.support.microsoft.com/profile/charlie.russel


"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
> Hi Tom,
> thank you very much for your replay.
>
> I read these articles before, but they didn't answer my question.
> I understand that my 32 bit application can take advantage of max 4 GB (in
> very particular condition) of the "Virtual Address Space"
> but I didn't understand if this "Virtaule Address" can be kept from every
> physical address space in case I have more than 4 GB of Physical RAM.
>
> "Tom Ferguson" wrote:
>
>> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64/wow64_implementation_details.asp
>> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>>
>> Tom
>> MSMVP
>> Windows Shell/User
>>
>>
>>
>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>> > Hi everybody.
>> >
>> > SCENARIO:
>> > Server with Windows x64 and 8 GB of physical ram;
>> > some 64-Bit application running;
>> > actual RAM usage 5 GB.
>> >
>> > QUESTION:
>> > If I add a (WOW64 compatible) 32bit application on this server, does
>> > it Work ?
>> > I mean: is WOW64 able to give some memory space of Physical RAM
>> > between the
>> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>> > memory
>> > limitation of the majority of the 32 bit application but...it is not
>> > the
>> > point of my question)
>> > If yes I'll be greatfull for some documentation link about it.
>> >
>> > Thank you in advance.
>> >
>> > Pierluigi
>>
>>


Re: WOW64 and Actual Phisical RAM Usage by Darrellg

Darrellg
Sat Jun 09 13:12:39 CDT 2007

Hello Charlie,
Good answer and a better one than I could have given.
Thanks,
Darrell Gorter[MSFT]

This posting is provided "AS IS" with no warranties, and confers no rights
--------------------
>From: "Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org>
>References: <861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com>
<#1YL6JeqHHA.3356@TK2MSFTNGP03.phx.gbl>
<8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>In-Reply-To: <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>Subject: Re: WOW64 and Actual Phisical RAM Usage
>Date: Fri, 8 Jun 2007 17:47:49 -0700
>Lines: 81
>Message-ID: <F692A23B-28E2-48F7-9EB0-3964F269EB46@microsoft.com>
>MIME-Version: 1.0
>Content-Type: text/plain;
> format=flowed;
> charset="utf-8";
> reply-type=original
>Content-Transfer-Encoding: 7bit
>X-Priority: 3
>X-MSMail-Priority: Normal
>X-Newsreader: Microsoft Windows Mail 6.0.6000.16386
>X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386
>X-MS-CommunityGroup-PostID: {F692A23B-28E2-48F7-9EB0-3964F269EB46}
>X-MS-CommunityGroup-ThreadID: 861ED15A-74E0-4358-852E-7B111F2F2818
>X-MS-CommunityGroup-ParentID: 8D097095-0703-4745-8B9D-E2772609AEAB
>Newsgroups: microsoft.public.windows.64bit.general
>Path: TK2MSFTNGHUB02.phx.gbl
>Xref: TK2MSFTNGHUB02.phx.gbl microsoft.public.windows.64bit.general:7219
>NNTP-Posting-Host: TK2MSFTNGHUB02.phx.gbl 127.0.0.1
>X-Tomcat-NG: microsoft.public.windows.64bit.general
>
>You have a mis-understanding of how memory addressing works and how that
>relates to RAM. They are not the same thing. x64 Windows versions can use
> >4GB of RAM (how much depends on the version), and all have an 8 TB
>application memory address space.
>
>The OS controls what applications are using what physical RAM. Regardless
of
>how much physical RAM you have, however, a 32-bit application has
available
>a 4 GB flat memory address space. If the application is written to take
>advantage of all the memory available, it will see 4GB. If it is a
>conventional 32-bit application, it will only see 2GB. 32-bit applications
>have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
>memory.
>
>Now, if you load a 64-bit application that uses 5 GB of memory (notice I'm
>NOT saying RAM here), and then want to load a 32-bit application that is
>large memory aware, it will see 4GB of memory. If you then load another
>32-bit application, it will see it's own 4 GB memory address space.
>
>So, what does this have to do with RAM? Windows will decide what portions
of
>any of those applications are running in RAM, what portion of RAM it keeps
>for itself, and what portion of any application it swaps out. This is the
>job of the OS. The application doesn't use RAM, it uses memory. The OS
>controls what memory is actually used for what purpose.
>
>--
>Charlie.
>http://msmvps.com/xperts64
>http://mvp.support.microsoft.com/profile/charlie.russel
>
>
>"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
>> Hi Tom,
>> thank you very much for your replay.
>>
>> I read these articles before, but they didn't answer my question.
>> I understand that my 32 bit application can take advantage of max 4 GB
(in
>> very particular condition) of the "Virtual Address Space"
>> but I didn't understand if this "Virtaule Address" can be kept from every
>> physical address space in case I have more than 4 GB of Physical RAM.
>>
>> "Tom Ferguson" wrote:
>>
>>> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>>> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>>>
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64
/wow64_implementation_details.asp
>>> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>>>
>>> Tom
>>> MSMVP
>>> Windows Shell/User
>>>
>>>
>>>
>>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>>> > Hi everybody.
>>> >
>>> > SCENARIO:
>>> > Server with Windows x64 and 8 GB of physical ram;
>>> > some 64-Bit application running;
>>> > actual RAM usage 5 GB.
>>> >
>>> > QUESTION:
>>> > If I add a (WOW64 compatible) 32bit application on this server, does
>>> > it Work ?
>>> > I mean: is WOW64 able to give some memory space of Physical RAM
>>> > between the
>>> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>>> > memory
>>> > limitation of the majority of the 32 bit application but...it is not
>>> > the
>>> > point of my question)
>>> > If yes I'll be greatfull for some documentation link about it.
>>> >
>>> > Thank you in advance.
>>> >
>>> > Pierluigi
>>>
>>>
>
>


Re: WOW64 and Actual Phisical RAM Usage by Charlie

Charlie
Sun Jun 10 13:05:50 CDT 2007

Thanks, Darrell. Though I suspect you are being modest - we've all
appreciated the answers you've provided here over the time we've been live.
You get all the tough ones - I just cherry pick the easy ones like this. ;)

--
Charlie.
http://msmvps.com/xperts64
http://mvp.support.microsoft.com/profile/charlie.russel


""Darrell Gorter[MSFT]"" <Darrellg@online.microsoft.com> wrote in message
news:ichjJHsqHHA.3656@TK2MSFTNGHUB02.phx.gbl...
> Hello Charlie,
> Good answer and a better one than I could have given.
> Thanks,
> Darrell Gorter[MSFT]
>
> This posting is provided "AS IS" with no warranties, and confers no rights
> --------------------
>>From: "Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org>
>>References: <861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com>
> <#1YL6JeqHHA.3356@TK2MSFTNGP03.phx.gbl>
> <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>In-Reply-To: <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>Subject: Re: WOW64 and Actual Phisical RAM Usage
>>Date: Fri, 8 Jun 2007 17:47:49 -0700
>>Lines: 81
>>Message-ID: <F692A23B-28E2-48F7-9EB0-3964F269EB46@microsoft.com>
>>MIME-Version: 1.0
>>Content-Type: text/plain;
>> format=flowed;
>> charset="utf-8";
>> reply-type=original
>>Content-Transfer-Encoding: 7bit
>>X-Priority: 3
>>X-MSMail-Priority: Normal
>>X-Newsreader: Microsoft Windows Mail 6.0.6000.16386
>>X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386
>>X-MS-CommunityGroup-PostID: {F692A23B-28E2-48F7-9EB0-3964F269EB46}
>>X-MS-CommunityGroup-ThreadID: 861ED15A-74E0-4358-852E-7B111F2F2818
>>X-MS-CommunityGroup-ParentID: 8D097095-0703-4745-8B9D-E2772609AEAB
>>Newsgroups: microsoft.public.windows.64bit.general
>>Path: TK2MSFTNGHUB02.phx.gbl
>>Xref: TK2MSFTNGHUB02.phx.gbl microsoft.public.windows.64bit.general:7219
>>NNTP-Posting-Host: TK2MSFTNGHUB02.phx.gbl 127.0.0.1
>>X-Tomcat-NG: microsoft.public.windows.64bit.general
>>
>>You have a mis-understanding of how memory addressing works and how that
>>relates to RAM. They are not the same thing. x64 Windows versions can use
>> >4GB of RAM (how much depends on the version), and all have an 8 TB
>>application memory address space.
>>
>>The OS controls what applications are using what physical RAM. Regardless
> of
>>how much physical RAM you have, however, a 32-bit application has
> available
>>a 4 GB flat memory address space. If the application is written to take
>>advantage of all the memory available, it will see 4GB. If it is a
>>conventional 32-bit application, it will only see 2GB. 32-bit applications
>>have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
>>memory.
>>
>>Now, if you load a 64-bit application that uses 5 GB of memory (notice I'm
>>NOT saying RAM here), and then want to load a 32-bit application that is
>>large memory aware, it will see 4GB of memory. If you then load another
>>32-bit application, it will see it's own 4 GB memory address space.
>>
>>So, what does this have to do with RAM? Windows will decide what portions
> of
>>any of those applications are running in RAM, what portion of RAM it keeps
>>for itself, and what portion of any application it swaps out. This is the
>>job of the OS. The application doesn't use RAM, it uses memory. The OS
>>controls what memory is actually used for what purpose.
>>
>>--
>>Charlie.
>>http://msmvps.com/xperts64
>>http://mvp.support.microsoft.com/profile/charlie.russel
>>
>>
>>"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
>>> Hi Tom,
>>> thank you very much for your replay.
>>>
>>> I read these articles before, but they didn't answer my question.
>>> I understand that my 32 bit application can take advantage of max 4 GB
> (in
>>> very particular condition) of the "Virtual Address Space"
>>> but I didn't understand if this "Virtaule Address" can be kept from
>>> every
>>> physical address space in case I have more than 4 GB of Physical RAM.
>>>
>>> "Tom Ferguson" wrote:
>>>
>>>> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>>>> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>>>>
> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64
> /wow64_implementation_details.asp
>>>> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>>>>
>>>> Tom
>>>> MSMVP
>>>> Windows Shell/User
>>>>
>>>>
>>>>
>>>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>>> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>>>> > Hi everybody.
>>>> >
>>>> > SCENARIO:
>>>> > Server with Windows x64 and 8 GB of physical ram;
>>>> > some 64-Bit application running;
>>>> > actual RAM usage 5 GB.
>>>> >
>>>> > QUESTION:
>>>> > If I add a (WOW64 compatible) 32bit application on this server, does
>>>> > it Work ?
>>>> > I mean: is WOW64 able to give some memory space of Physical RAM
>>>> > between the
>>>> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>>>> > memory
>>>> > limitation of the majority of the 32 bit application but...it is not
>>>> > the
>>>> > point of my question)
>>>> > If yes I'll be greatfull for some documentation link about it.
>>>> >
>>>> > Thank you in advance.
>>>> >
>>>> > Pierluigi
>>>>
>>>>
>>
>>
>


Re: WOW64 and Actual Phisical RAM Usage by John

John
Mon Jun 11 19:08:24 CDT 2007

Now, who's being modest. You have sure shown the light on your share of
hard problems.

"Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org> wrote in message
news:4CC319A9-694B-490F-80ED-F0DA64FC387C@microsoft.com...
> Thanks, Darrell. Though I suspect you are being modest - we've all
> appreciated the answers you've provided here over the time we've been
> live. You get all the tough ones - I just cherry pick the easy ones like
> this. ;)
>
> --
> Charlie.
> http://msmvps.com/xperts64
> http://mvp.support.microsoft.com/profile/charlie.russel
>
>
> ""Darrell Gorter[MSFT]"" <Darrellg@online.microsoft.com> wrote in message
> news:ichjJHsqHHA.3656@TK2MSFTNGHUB02.phx.gbl...
>> Hello Charlie,
>> Good answer and a better one than I could have given.
>> Thanks,
>> Darrell Gorter[MSFT]
>>
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights
>> --------------------
>>>From: "Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org>
>>>References: <861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com>
>> <#1YL6JeqHHA.3356@TK2MSFTNGP03.phx.gbl>
>> <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>>In-Reply-To: <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>>Subject: Re: WOW64 and Actual Phisical RAM Usage
>>>Date: Fri, 8 Jun 2007 17:47:49 -0700
>>>Lines: 81
>>>Message-ID: <F692A23B-28E2-48F7-9EB0-3964F269EB46@microsoft.com>
>>>MIME-Version: 1.0
>>>Content-Type: text/plain;
>>> format=flowed;
>>> charset="utf-8";
>>> reply-type=original
>>>Content-Transfer-Encoding: 7bit
>>>X-Priority: 3
>>>X-MSMail-Priority: Normal
>>>X-Newsreader: Microsoft Windows Mail 6.0.6000.16386
>>>X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386
>>>X-MS-CommunityGroup-PostID: {F692A23B-28E2-48F7-9EB0-3964F269EB46}
>>>X-MS-CommunityGroup-ThreadID: 861ED15A-74E0-4358-852E-7B111F2F2818
>>>X-MS-CommunityGroup-ParentID: 8D097095-0703-4745-8B9D-E2772609AEAB
>>>Newsgroups: microsoft.public.windows.64bit.general
>>>Path: TK2MSFTNGHUB02.phx.gbl
>>>Xref: TK2MSFTNGHUB02.phx.gbl microsoft.public.windows.64bit.general:7219
>>>NNTP-Posting-Host: TK2MSFTNGHUB02.phx.gbl 127.0.0.1
>>>X-Tomcat-NG: microsoft.public.windows.64bit.general
>>>
>>>You have a mis-understanding of how memory addressing works and how that
>>>relates to RAM. They are not the same thing. x64 Windows versions can use
>>> >4GB of RAM (how much depends on the version), and all have an 8 TB
>>>application memory address space.
>>>
>>>The OS controls what applications are using what physical RAM. Regardless
>> of
>>>how much physical RAM you have, however, a 32-bit application has
>> available
>>>a 4 GB flat memory address space. If the application is written to take
>>>advantage of all the memory available, it will see 4GB. If it is a
>>>conventional 32-bit application, it will only see 2GB. 32-bit
>>>applications
>>>have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
>>>memory.
>>>
>>>Now, if you load a 64-bit application that uses 5 GB of memory (notice
>>>I'm
>>>NOT saying RAM here), and then want to load a 32-bit application that is
>>>large memory aware, it will see 4GB of memory. If you then load another
>>>32-bit application, it will see it's own 4 GB memory address space.
>>>
>>>So, what does this have to do with RAM? Windows will decide what portions
>> of
>>>any of those applications are running in RAM, what portion of RAM it
>>>keeps
>>>for itself, and what portion of any application it swaps out. This is the
>>>job of the OS. The application doesn't use RAM, it uses memory. The OS
>>>controls what memory is actually used for what purpose.
>>>
>>>--
>>>Charlie.
>>>http://msmvps.com/xperts64
>>>http://mvp.support.microsoft.com/profile/charlie.russel
>>>
>>>
>>>"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>>news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
>>>> Hi Tom,
>>>> thank you very much for your replay.
>>>>
>>>> I read these articles before, but they didn't answer my question.
>>>> I understand that my 32 bit application can take advantage of max 4 GB
>> (in
>>>> very particular condition) of the "Virtual Address Space"
>>>> but I didn't understand if this "Virtaule Address" can be kept from
>>>> every
>>>> physical address space in case I have more than 4 GB of Physical RAM.
>>>>
>>>> "Tom Ferguson" wrote:
>>>>
>>>>> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>>>>> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>>>>>
>> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64
>> /wow64_implementation_details.asp
>>>>> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>>>>>
>>>>> Tom
>>>>> MSMVP
>>>>> Windows Shell/User
>>>>>
>>>>>
>>>>>
>>>>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>>>> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>>>>> > Hi everybody.
>>>>> >
>>>>> > SCENARIO:
>>>>> > Server with Windows x64 and 8 GB of physical ram;
>>>>> > some 64-Bit application running;
>>>>> > actual RAM usage 5 GB.
>>>>> >
>>>>> > QUESTION:
>>>>> > If I add a (WOW64 compatible) 32bit application on this server, does
>>>>> > it Work ?
>>>>> > I mean: is WOW64 able to give some memory space of Physical RAM
>>>>> > between the
>>>>> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>>>>> > memory
>>>>> > limitation of the majority of the 32 bit application but...it is not
>>>>> > the
>>>>> > point of my question)
>>>>> > If yes I'll be greatfull for some documentation link about it.
>>>>> >
>>>>> > Thank you in advance.
>>>>> >
>>>>> > Pierluigi
>>>>>
>>>>>
>>>
>>>
>>
>


Re: WOW64 and Actual Phisical RAM Usage by Charlie

Charlie
Tue Jun 12 00:49:10 CDT 2007

Oh, we all struggle along here. And goodness knows we have had some
interesting problems to discover the answers to. My favourite problem to
this day, however, is still the 32-bit internet connectivity fix for nvidia
mobos. I wish I could remember who originally came up with the solution, but
it's lost in antiquity now. Which doesn't mean I haven't had to haul that
answer out lately - it still comes up!

--
Charlie.
http://msmvps.com/xperts64
http://mvp.support.microsoft.com/profile/charlie.russel


"John Barnes" <jbarnes@email.net> wrote in message
news:eoAMTXIrHHA.3456@TK2MSFTNGP02.phx.gbl...
> Now, who's being modest. You have sure shown the light on your share of
> hard problems.
>
> "Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org> wrote in message
> news:4CC319A9-694B-490F-80ED-F0DA64FC387C@microsoft.com...
>> Thanks, Darrell. Though I suspect you are being modest - we've all
>> appreciated the answers you've provided here over the time we've been
>> live. You get all the tough ones - I just cherry pick the easy ones like
>> this. ;)
>>
>> --
>> Charlie.
>> http://msmvps.com/xperts64
>> http://mvp.support.microsoft.com/profile/charlie.russel
>>
>>
>> ""Darrell Gorter[MSFT]"" <Darrellg@online.microsoft.com> wrote in message
>> news:ichjJHsqHHA.3656@TK2MSFTNGHUB02.phx.gbl...
>>> Hello Charlie,
>>> Good answer and a better one than I could have given.
>>> Thanks,
>>> Darrell Gorter[MSFT]
>>>
>>> This posting is provided "AS IS" with no warranties, and confers no
>>> rights
>>> --------------------
>>>>From: "Charlie Russel - MVP" <charlie@mvKILLALLSPAMMERSps.org>
>>>>References: <861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com>
>>> <#1YL6JeqHHA.3356@TK2MSFTNGP03.phx.gbl>
>>> <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>>>In-Reply-To: <8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com>
>>>>Subject: Re: WOW64 and Actual Phisical RAM Usage
>>>>Date: Fri, 8 Jun 2007 17:47:49 -0700
>>>>Lines: 81
>>>>Message-ID: <F692A23B-28E2-48F7-9EB0-3964F269EB46@microsoft.com>
>>>>MIME-Version: 1.0
>>>>Content-Type: text/plain;
>>>> format=flowed;
>>>> charset="utf-8";
>>>> reply-type=original
>>>>Content-Transfer-Encoding: 7bit
>>>>X-Priority: 3
>>>>X-MSMail-Priority: Normal
>>>>X-Newsreader: Microsoft Windows Mail 6.0.6000.16386
>>>>X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386
>>>>X-MS-CommunityGroup-PostID: {F692A23B-28E2-48F7-9EB0-3964F269EB46}
>>>>X-MS-CommunityGroup-ThreadID: 861ED15A-74E0-4358-852E-7B111F2F2818
>>>>X-MS-CommunityGroup-ParentID: 8D097095-0703-4745-8B9D-E2772609AEAB
>>>>Newsgroups: microsoft.public.windows.64bit.general
>>>>Path: TK2MSFTNGHUB02.phx.gbl
>>>>Xref: TK2MSFTNGHUB02.phx.gbl microsoft.public.windows.64bit.general:7219
>>>>NNTP-Posting-Host: TK2MSFTNGHUB02.phx.gbl 127.0.0.1
>>>>X-Tomcat-NG: microsoft.public.windows.64bit.general
>>>>
>>>>You have a mis-understanding of how memory addressing works and how that
>>>>relates to RAM. They are not the same thing. x64 Windows versions can
>>>>use
>>>> >4GB of RAM (how much depends on the version), and all have an 8 TB
>>>>application memory address space.
>>>>
>>>>The OS controls what applications are using what physical RAM.
>>>>Regardless
>>> of
>>>>how much physical RAM you have, however, a 32-bit application has
>>> available
>>>>a 4 GB flat memory address space. If the application is written to take
>>>>advantage of all the memory available, it will see 4GB. If it is a
>>>>conventional 32-bit application, it will only see 2GB. 32-bit
>>>>applications
>>>>have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
>>>>memory.
>>>>
>>>>Now, if you load a 64-bit application that uses 5 GB of memory (notice
>>>>I'm
>>>>NOT saying RAM here), and then want to load a 32-bit application that is
>>>>large memory aware, it will see 4GB of memory. If you then load another
>>>>32-bit application, it will see it's own 4 GB memory address space.
>>>>
>>>>So, what does this have to do with RAM? Windows will decide what
>>>>portions
>>> of
>>>>any of those applications are running in RAM, what portion of RAM it
>>>>keeps
>>>>for itself, and what portion of any application it swaps out. This is
>>>>the
>>>>job of the OS. The application doesn't use RAM, it uses memory. The OS
>>>>controls what memory is actually used for what purpose.
>>>>
>>>>--
>>>>Charlie.
>>>>http://msmvps.com/xperts64
>>>>http://mvp.support.microsoft.com/profile/charlie.russel
>>>>
>>>>
>>>>"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>>>news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
>>>>> Hi Tom,
>>>>> thank you very much for your replay.
>>>>>
>>>>> I read these articles before, but they didn't answer my question.
>>>>> I understand that my 32 bit application can take advantage of max 4 GB
>>> (in
>>>>> very particular condition) of the "Virtual Address Space"
>>>>> but I didn't understand if this "Virtaule Address" can be kept from
>>>>> every
>>>>> physical address space in case I have more than 4 GB of Physical
>>>>> RAM.
>>>>>
>>>>> "Tom Ferguson" wrote:
>>>>>
>>>>>> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>>>>>> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>>>>>>
>>> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64
>>> /wow64_implementation_details.asp
>>>>>> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>>>>>>
>>>>>> Tom
>>>>>> MSMVP
>>>>>> Windows Shell/User
>>>>>>
>>>>>>
>>>>>>
>>>>>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>>>>>> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>>>>>> > Hi everybody.
>>>>>> >
>>>>>> > SCENARIO:
>>>>>> > Server with Windows x64 and 8 GB of physical ram;
>>>>>> > some 64-Bit application running;
>>>>>> > actual RAM usage 5 GB.
>>>>>> >
>>>>>> > QUESTION:
>>>>>> > If I add a (WOW64 compatible) 32bit application on this server,
>>>>>> > does
>>>>>> > it Work ?
>>>>>> > I mean: is WOW64 able to give some memory space of Physical RAM
>>>>>> > between the
>>>>>> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>>>>>> > memory
>>>>>> > limitation of the majority of the 32 bit application but...it is
>>>>>> > not
>>>>>> > the
>>>>>> > point of my question)
>>>>>> > If yes I'll be greatfull for some documentation link about it.
>>>>>> >
>>>>>> > Thank you in advance.
>>>>>> >
>>>>>> > Pierluigi
>>>>>>
>>>>>>
>>>>
>>>>
>>>
>>
>


Re: WOW64 and Actual Phisical RAM Usage by Pierluigi

Pierluigi
Tue Jun 12 03:34:09 CDT 2007

Hi Charlie,

your answer is very apprecieted.

I think you are right about my mis-undertstanding of how memory addressing
works.

And ... sorry but I would like to be sure about understanding your answer
(sorry but I'm from italy and my english is not so well).

So: in case I use a 32 BIT OS like Windows2003 Enterprise Edition, plus,
numerous 32 bit legacy application using (each application) from 2 to 4 GB
memory, can I benefit installing more than 4 GB of RAM on the server ?

Please.... be patient...but I would like to resolve my doubts once for all....

Pierluigi

"Charlie Russel - MVP" wrote:

> You have a mis-understanding of how memory addressing works and how that
> relates to RAM. They are not the same thing. x64 Windows versions can use
> >4GB of RAM (how much depends on the version), and all have an 8 TB
> application memory address space.
>
> The OS controls what applications are using what physical RAM. Regardless of
> how much physical RAM you have, however, a 32-bit application has available
> a 4 GB flat memory address space. If the application is written to take
> advantage of all the memory available, it will see 4GB. If it is a
> conventional 32-bit application, it will only see 2GB. 32-bit applications
> have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
> memory.
>
> Now, if you load a 64-bit application that uses 5 GB of memory (notice I'm
> NOT saying RAM here), and then want to load a 32-bit application that is
> large memory aware, it will see 4GB of memory. If you then load another
> 32-bit application, it will see it's own 4 GB memory address space.
>
> So, what does this have to do with RAM? Windows will decide what portions of
> any of those applications are running in RAM, what portion of RAM it keeps
> for itself, and what portion of any application it swaps out. This is the
> job of the OS. The application doesn't use RAM, it uses memory. The OS
> controls what memory is actually used for what purpose.
>
> --
> Charlie.
> http://msmvps.com/xperts64
> http://mvp.support.microsoft.com/profile/charlie.russel
>
>
> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
> news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
> > Hi Tom,
> > thank you very much for your replay.
> >
> > I read these articles before, but they didn't answer my question.
> > I understand that my 32 bit application can take advantage of max 4 GB (in
> > very particular condition) of the "Virtual Address Space"
> > but I didn't understand if this "Virtaule Address" can be kept from every
> > physical address space in case I have more than 4 GB of Physical RAM.
> >
> > "Tom Ferguson" wrote:
> >
> >> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
> >> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
> >> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64/wow64_implementation_details.asp
> >> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
> >>
> >> Tom
> >> MSMVP
> >> Windows Shell/User
> >>
> >>
> >>
> >> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
> >> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
> >> > Hi everybody.
> >> >
> >> > SCENARIO:
> >> > Server with Windows x64 and 8 GB of physical ram;
> >> > some 64-Bit application running;
> >> > actual RAM usage 5 GB.
> >> >
> >> > QUESTION:
> >> > If I add a (WOW64 compatible) 32bit application on this server, does
> >> > it Work ?
> >> > I mean: is WOW64 able to give some memory space of Physical RAM
> >> > between the
> >> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
> >> > memory
> >> > limitation of the majority of the 32 bit application but...it is not
> >> > the
> >> > point of my question)
> >> > If yes I'll be greatfull for some documentation link about it.
> >> >
> >> > Thank you in advance.
> >> >
> >> > Pierluigi
> >>
> >>
>

Re: WOW64 and Actual Phisical RAM Usage by Charlie

Charlie
Tue Jun 12 08:21:42 CDT 2007

Using a 32-bit version of Windows Server 2003 Enterprise Edition, you can
take advantage of >4gb of RAM. But _only_ by using something called PAE
which is a method for swapping chunks of memory in and out of a narrow
window within the 4GB of virtual memory address space that is supported by
32-bit Windows. This is of little or no benefit for legacy, conventional,
32-bit programs such as Office, but may provide some benefit for
applications written to take explicit advantage of it - SQL Server comes to
mind.

For running multiple legacy applications as you describe, you won't see much
if any benefit.

--
Charlie.
http://msmvps.com/blogs/xperts64

"Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
news:1C0681D2-53B9-477D-AF17-311914298A0B@microsoft.com...
> Hi Charlie,
>
> your answer is very apprecieted.
>
> I think you are right about my mis-undertstanding of how memory addressing
> works.
>
> And ... sorry but I would like to be sure about understanding your answer
> (sorry but I'm from italy and my english is not so well).
>
> So: in case I use a 32 BIT OS like Windows2003 Enterprise Edition, plus,
> numerous 32 bit legacy application using (each application) from 2 to 4 GB
> memory, can I benefit installing more than 4 GB of RAM on the server ?
>
> Please.... be patient...but I would like to resolve my doubts once for
> all....
>
> Pierluigi
>
> "Charlie Russel - MVP" wrote:
>
>> You have a mis-understanding of how memory addressing works and how that
>> relates to RAM. They are not the same thing. x64 Windows versions can use
>> >4GB of RAM (how much depends on the version), and all have an 8 TB
>> application memory address space.
>>
>> The OS controls what applications are using what physical RAM. Regardless
>> of
>> how much physical RAM you have, however, a 32-bit application has
>> available
>> a 4 GB flat memory address space. If the application is written to take
>> advantage of all the memory available, it will see 4GB. If it is a
>> conventional 32-bit application, it will only see 2GB. 32-bit
>> applications
>> have to be compiled with the LARGEMEMORYADDRESSAWARE flag to see >2GB of
>> memory.
>>
>> Now, if you load a 64-bit application that uses 5 GB of memory (notice
>> I'm
>> NOT saying RAM here), and then want to load a 32-bit application that is
>> large memory aware, it will see 4GB of memory. If you then load another
>> 32-bit application, it will see it's own 4 GB memory address space.
>>
>> So, what does this have to do with RAM? Windows will decide what portions
>> of
>> any of those applications are running in RAM, what portion of RAM it
>> keeps
>> for itself, and what portion of any application it swaps out. This is the
>> job of the OS. The application doesn't use RAM, it uses memory. The OS
>> controls what memory is actually used for what purpose.
>>
>> --
>> Charlie.
>> http://msmvps.com/xperts64
>> http://mvp.support.microsoft.com/profile/charlie.russel
>>
>>
>> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>> news:8D097095-0703-4745-8B9D-E2772609AEAB@microsoft.com...
>> > Hi Tom,
>> > thank you very much for your replay.
>> >
>> > I read these articles before, but they didn't answer my question.
>> > I understand that my 32 bit application can take advantage of max 4 GB
>> > (in
>> > very particular condition) of the "Virtual Address Space"
>> > but I didn't understand if this "Virtaule Address" can be kept from
>> > every
>> > physical address space in case I have more than 4 GB of Physical RAM.
>> >
>> > "Tom Ferguson" wrote:
>> >
>> >> http://www.microsoft.com/whdc/system/platform/64bit/WoW64_bestprac.mspx
>> >> http://msdn2.microsoft.com/en-us/library/aa366778.aspx
>> >> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64/wow64_implementation_details.asp
>> >> http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
>> >>
>> >> Tom
>> >> MSMVP
>> >> Windows Shell/User
>> >>
>> >>
>> >>
>> >> "Pierluigi" <Pierluigi@discussions.microsoft.com> wrote in message
>> >> news:861ED15A-74E0-4358-852E-7B111F2F2818@microsoft.com...
>> >> > Hi everybody.
>> >> >
>> >> > SCENARIO:
>> >> > Server with Windows x64 and 8 GB of physical ram;
>> >> > some 64-Bit application running;
>> >> > actual RAM usage 5 GB.
>> >> >
>> >> > QUESTION:
>> >> > If I add a (WOW64 compatible) 32bit application on this server, does
>> >> > it Work ?
>> >> > I mean: is WOW64 able to give some memory space of Physical RAM
>> >> > between the
>> >> > 5th and the 8th gigabytes (I Know about the 2 to 4 GB adressable
>> >> > memory
>> >> > limitation of the majority of the 32 bit application but...it is not
>> >> > the
>> >> > point of my question)
>> >> > If yes I'll be greatfull for some documentation link about it.
>> >> >
>> >> > Thank you in advance.
>> >> >
>> >> > Pierluigi
>> >>
>> >>
>>


Re: WOW64 and Actual Phisical RAM Usage by jorgen

jorgen
Tue Jun 12 09:10:14 CDT 2007

Charlie Russel - MVP wrote:
> Using a 32-bit version of Windows Server 2003 Enterprise Edition, you
> can take advantage of >4gb of RAM. But _only_ by using something called
> PAE which is a method for swapping chunks of memory in and out of a
> narrow window within the 4GB of virtual memory address space that is
> supported by 32-bit Windows. This is of little or no benefit for legacy,
> conventional, 32-bit programs such as Office, but may provide some
> benefit for applications written to take explicit advantage of it - SQL
> Server comes to mind.
>
> For running multiple legacy applications as you describe, you won't see
> much if any benefit.
>

That is not what you initially said, was it?

Anyways, the process only sees virtual addresses, all going from 0-4GB,
regardless where in physical memory it resides. Only the memory manager
sees the 36-bit physical address, and therefore the application doesn't
need to be written differently.