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The Memory limit of 32 bit applications on a 64 bit OS is 2 GB or 4 GB with /LARGEADDRESSAWARE.

Source: How much memory can a 32 bit process access on a 64 bit operating system?

MY QUESTION: Is that limit PER process, or that limit is for all combined 32-bit processes?

If three 32 bit processes are running (on a 64 bit OS), can I use up to 12 GB of memory (4 each) or will it be limited to 4 GB shared between all of them?

Community
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Marc477
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2 Answers2

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Processes do not need to use the same address space. That means multiple 32-bit applications running simultaneously can effectively use all the memory available on a 64-bit machine.

SoftwareFactor
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  • Also, note that the address space does not limit the amount of memory that an application can use; you can create file mappings (see [CreateFileMapping](http://msdn.microsoft.com/en-us/library/windows/desktop/aa366537(v=vs.85).aspx) for details) that allow you to use part of your address space to access a memory block of arbitrary size. (You do not need to create an actual file, and the contents will not be swapped to disk if there is enough physical RAM to hold them.) – Harry Johnston May 17 '14 at 04:36
  • By experience, if application is running in background, all memory of instances running simultaneously canot excede 1.3GB. For ex: When you start A.exe from Windows task manager, all the memory in all the children are counted as belonging to "A.exe". – Diogo Rodrigues Sep 20 '22 at 17:52
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My experience with 64 bit windows 8 is there is shared limit for 32 bit applications. I frequently got "Your computer is low on memory" error with only 50% of ram used until I switched to 64 bit apps.

Cmazay
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  • As it’s currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Nov 07 '21 at 20:28