can x86 applications on x64 PC access more than 4GB RAM ?

Question

I heard that 32 bit OS can access only 4GB of RAM and 64bit can access more than

I am currently running on 32 bit windows7 with 6GB RAM. It can't access 6GB fully right now.

I can shorten my question as should I need to download 64 apps for windows7 x64 for full access of 6GB RAM ? or 32 bits apps itself too access 6G RAM ?

Answer 1

"can x86 applications on x64 PC access more than 4GB RAM ?"



If one byte is the smallest addressable unit of memory, then the program itself can only address 4,294,967,295 bytes (providing 0 is an invalid index) in 32 bits.



I suggest you run programs that are built for your architecture, instead of relying on emulation.

Answer 2

Nothing like that. But 32-Bit can access max of 3.2GB not 4GB. So, to use full 6GB its a good suggestion to use 64-Bit. And most 32-Bit apps run fine on 64-Bit. So, check it first and then download those apps which dont run on 64-Bit.

Answer 3

You can use more than 4gb's of memory under 32-bit system (I have 32-bit win7 and have acces to all 4 gb's, though usually 3,25gb's can be used), but it would be necessary to make some manipulations with your OS. First of all, you have to patch some of your system files (http://www.k-max.name/wp-content/uploads/2010/08/4gb.zip - use this file, readme file inside, follow exactly to the instructions).

After that type in command console with administrator's rights

bcdedit /export "C:\BCDBackup"

press "enter"

after that type

bcdedit /set IncreaseUserVa 2500

press "enter". - this will allow to use more than 2 gb's of memory by applications

I've made such manipulations and now I use all 4 gb's of RAM, i just don't want to install 64-bit win7 and before upgrade to 4gb's I had 3gb's. But some applications have 64-bit versions and are intended to use only inder 64-bit system.

Answer 4

The OS accesses the RAM, not the apps, so don't worry about x64 apps, which are rare anyway.