memory limit on 32-bit applications running on 64-bit windows?

[crichmon]

It is my understanding that, with Windows 32-bit, the OS can only access up to 4gb of Ram. To get access to larger amounts of Ram (such as 8, 16, or 32gb), one must have Windows 64-bit installed.

Regarding applications though... if running a 32-bit application on 64-bit Windows, is the application limited to only being able to use 4gb of ram?

 

[TwoCables]

Nope because 32-bit applications won't ever need more than 4 GB.

 

[pallesenw]

Yes, if the application is marked as large address aware, otherwise it stops at 2GB for compatibility reasons.

Indirectly it can use more, if you take file cache etc. into account.

 

[Britton30]

Well this is definitive, one yes and one no. :sarc:

 

[yvesj]

really 32 bits only need 4 gbs .but you will only get about 3.08 of of the 4 .
now on 64 bits it 16 on home premium but on pro is it 192 gbs
were do you get them now ????? i thing it only for server

 

[logicearth]

Alright lets clear this up. A 32-bit application on Windows x64 can use up to 2 GBs. Now applications that are Large Address Aware, the developer has set this when building the application, can use up to 4GBs. A 32-bit application cannot go any higher then that.

 

[crichmon]

Thanks!

 

[geoffrose]

Even if the application isnt Large Address Aware you can patch it with this program
NTCore's Homepage

Ive only tested it with one app but it did what it says

 

[MilesAhead]

Alright lets clear this up. A 32-bit application on Windows x64 can use up to 2 GBs. Now applications that are Large Address Aware, the developer has set this when building the application, can use up to 4GBs. A 32-bit application cannot go any higher then that.

It is kind of curious that not one OS author, even in demo mode, that I ever heard of, made use of the Segment Descriptor Table on 386 and higher processors. A 48 bit address space is possible using them. But I guess masochism isn't as popular as it was back in the 80s.

 

[LMiller7]

Even if the application isnt Large Address Aware you can patch it with this program
NTCore's Homepage

Ive only tested it with one app but it did what it says

The program is simply modifying the header of the application to set the Large Address Aware flag. This indicates to the OS that the application can handle virtual addresses over 2 GB. The problem is that you may be forcing the application to lie about it's capabilities. Ensuring than an application really is compatible requires a major effort by a developer and cannot really be done without source code access. If the application tells the OS that it is compatible and it really isn't it could have dire results. The application is likely to crash, or worse, silently corrupt it's data. And because of the way the OS allocates address space the problem may only occur under specific and unusual conditions.

 

[oneskrewluse]

i believe the 192gb max on ultimate is for future proofing the os personally

if your running a 64bit version of windows most software out there has a x86(32b) and a 64 (x64) versions to help implement the addition of ram and processor limits

but to answer your original question 32bit programs are still limited to 2 gb of ram no matter if your running 64 bit or not

 

[TwoCables]

i believe the 192gb max on ultimate is for future proofing the os personally

if your running a 64bit version of windows most software out there has a x86(32b) and a 64 (x64) versions to help implement the addition of ram and processor limits

but to answer your original question 32bit programs are still limited to 2 gb of ram no matter if your running 64 bit or not

Ultimate is designed to be able to run on computers that no home user would ever be able to afford.