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Are 32 bit apps still limited to 3g per process on x64 systems? What about
64 bit apps? Whats the limit per process?

THanks,
KG

32 bit applications are limited to 4GB if they are compiled with the
/LARGEMEMORYADDRESSAWARE flag (which was required to get 3GB under 32-bit
Windows). No command line switches or other application changes are required
to give that 4gb, assuming the application was written to recognize the extra
memory at all.

64-bit processes have access to 8TB of virtual memory address space.


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


news.microsoft.com wrote:
> Are 32 bit apps still limited to 3g per process on x64 systems? What
> about 64 bit apps? Whats the limit per process?
>
> THanks,
> KG

Is there a technical advantage NOT to use the /LARGEMEMORYADDRESSAWARE
flag. I have a lot of programs which obviously don't have it set. Seems
strange a $200 program wouldn't have it set. Maybe just laziness when
upgrading from old versions.


"Charlie Russel - MVP" <> wrote in message
news:e$...
> 32 bit applications are limited to 4GB if they are compiled with the fla
> /LARGEMEMORYADDRESSAWARE g (which was required to get 3GB under 32-bit
> Windows). No command line switches or other application changes are
> required to give that 4gb, assuming the application was written to
> recognize the extra memory at all.
>
> 64-bit processes have access to 8TB of virtual memory address space.
>
>
> --
> Charlie.
> http://www.msmvps.com/xperts64/
>
>
> news.microsoft.com wrote:
>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>> about 64 bit apps? Whats the limit per process?
>>
>> THanks,
>> KG
>
>

Probably laziness, but I'm not enough of a programmer to know. OTOH, there
can be good reasons to NOT run 32-bit Windows with the boot time /3GB switch
(which is required in 32-bit windows to make the extra memory available to
applications). Using this switch severely constrains the available memory for
the OS and can be a big problem with an I/O intensive system. So you might
well do it on a SQL Server or Exchange box, that is doing nothing else, and
where the application is basically handling the I/O. But no way on a terminal
server box, for example, or a file server.

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


John Barnes wrote:
> Is there a technical advantage NOT to use the /LARGEMEMORYADDRESSAWARE
> flag. I have a lot of programs which
> obviously don't have it set. Seems strange a $200 program wouldn't
> have it set. Maybe just laziness when upgrading from old versions.
>
>
> "Charlie Russel - MVP" <> wrote in
> message news:e$...
>> 32 bit applications are limited to 4GB if they are compiled with the
>> fla /LARGEMEMORYADDRESSAWARE g (which was required to get 3GB under
>> 32-bit Windows). No command line switches or other application
>> changes are required to give that 4gb, assuming the application was
>> written to recognize the extra memory at all.
>>
>> 64-bit processes have access to 8TB of virtual memory address space.
>>
>>
>> --
>> Charlie.
>> http://www.msmvps.com/xperts64/
>>
>>
>> news.microsoft.com wrote:
>>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>>> about 64 bit apps? Whats the limit per process?
>>>
>>> THanks,
>>> KG

ACTUALLY, Win XP x86 can only access 128GB in this release using native
64bit apps.


"Charlie Russel - MVP" <> wrote in message
news:e$...
> 32 bit applications are limited to 4GB if they are compiled with the
> /LARGEMEMORYADDRESSAWARE flag (which was required to get 3GB under 32-bit
> Windows). No command line switches or other application changes are
> required to give that 4gb, assuming the application was written to
> recognize the extra memory at all.
>
> 64-bit processes have access to 8TB of virtual memory address space.
>
>
> --
> Charlie.
> http://www.msmvps.com/xperts64/
>
>
> news.microsoft.com wrote:
>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>> about 64 bit apps? Whats the limit per process?
>>
>> THanks,
>> KG
>
>

Read carefully before you yell about something. I said 8TB of virtual memory
address space. That is correct. It will only support 128 GB of physical RAM
(in XP - Server is different). RAM and virtual memory address space are NOT
the same thing. (and it x64, not x86, BTW.)

the issue for many applications has not been RAM but virtual memory address
space, which is limited to 4GB total for 32-bit Windows without some
interesting workarounds. Of that 4GB of virtual memory address space,
normally 2GB is reserved for the OS itself, with the other 2gb available for
applications. If the application is written to take advantage of it, then you
can constrain the OS into 1GB, leaving 3GB of virtual memory address space
for application processes. But many applications are not written to take
advantage, and they will only ever see 2gb of virtual memory address space.


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


Draco Paladine wrote:
> ACTUALLY, Win XP x86 can only access 128GB in this release using
> native 64bit apps.
>
>
> "Charlie Russel - MVP" <> wrote in
> message news:e$...
>> 32 bit applications are limited to 4GB if they are compiled with the
>> /LARGEMEMORYADDRESSAWARE flag (which was required to get 3GB under
>> 32-bit Windows). No command line switches or other application
>> changes are required to give that 4gb, assuming the application was
>> written to recognize the extra memory at all.
>>
>> 64-bit processes have access to 8TB of virtual memory address space.
>>
>>
>> --
>> Charlie.
>> http://www.msmvps.com/xperts64/
>>
>>
>> news.microsoft.com wrote:
>>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>>> about 64 bit apps? Whats the limit per process?
>>>
>>> THanks,
>>> KG

What about the .net framework 1.1. Anyone know if that will give me any
more memory usage by switching to x64? I know the 2.0 framework is supposed
to but it wont be out for a few months.
KG

"Draco Paladine" <> wrote in message
news:...
> ACTUALLY, Win XP x86 can only access 128GB in this release using native
> 64bit apps.
>
>
> "Charlie Russel - MVP" <> wrote in message
> news:e$...
>> 32 bit applications are limited to 4GB if they are compiled with the
>> /LARGEMEMORYADDRESSAWARE flag (which was required to get 3GB under 32-bit
>> Windows). No command line switches or other application changes are
>> required to give that 4gb, assuming the application was written to
>> recognize the extra memory at all.
>>
>> 64-bit processes have access to 8TB of virtual memory address space.
>>
>>
>> --
>> Charlie.
>> http://www.msmvps.com/xperts64/
>>
>>
>> news.microsoft.com wrote:
>>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>>> about 64 bit apps? Whats the limit per process?
>>>
>>> THanks,
>>> KG
>>
>>
>
>

yes. 32-bit applications compiled to take advantage of virtual memory address
space beyond 2GB will see a full 4GB under WOW64. See my Deployment
whitepaper at
http://www.microsoft.com/windowsserv...64/deploy.mspx. And the
Benefits one as well.

--
Please, all replies to the newsgroup.
======================
Charlie.
http://www.msmvps.com/xperts64/


kevin goff wrote:
> What about the .net framework 1.1. Anyone know if that will give me
> any more memory usage by switching to x64? I know the 2.0 framework
> is supposed to but it wont be out for a few months.
> KG
>
> "Draco Paladine" <> wrote in message
> news:...
>> ACTUALLY, Win XP x86 can only access 128GB in this release using
>> native 64bit apps.
>>
>>
>> "Charlie Russel - MVP" <> wrote in
>> message news:e$...
>>> 32 bit applications are limited to 4GB if they are compiled with the
>>> /LARGEMEMORYADDRESSAWARE flag (which was required to get 3GB under
>>> 32-bit Windows). No command line switches or other application
>>> changes are required to give that 4gb, assuming the application was
>>> written to recognize the extra memory at all.
>>>
>>> 64-bit processes have access to 8TB of virtual memory address space.
>>>
>>>
>>> --
>>> Charlie.
>>> http://www.msmvps.com/xperts64/
>>>
>>>
>>> news.microsoft.com wrote:
>>>> Are 32 bit apps still limited to 3g per process on x64 systems? What
>>>> about 64 bit apps? Whats the limit per process?
>>>>
>>>> THanks,
>>>> KG