I never stated it removed any barrier but now reports the total amount installed. And the barrier surrounds the 3gb mark not 4gb.
Yes you did!
Its 4gbs. not 3gbs.! If its 3gbs. then explain how 2000/XP and Vista 32bit can utilize more than 3gbs. I,ve got XP on a system right now that has 4gbs. and has 3.25gbs of usable memory. When you run 4gbs. or more the system will reserve memory for hardware addresses which will put you in under 4gbs of usable memory.
From you own link.
If you install ((4Gb)), there is no way to make all of the RAM between 3Gb and 4Gb available without installing a 64-bit OS
The reason why not quite all of even
three gigabytes is usable is related to the ((4Gb)) problem, as we'll see
http://msdn.microsoft.com/en-us/library/aa366778.aspx#memory_limits
32-bit Windows uses a flat memory address space, thus is limited to 4 GB of memory addresses. This is divided up 2 GB for individual user programs, and 2 GB for the operating system. It doesn't matter if you have 4 GB of RAM, or 512 Mb of RAM, it's the same virtual memory address space. This means that in order to directly address the memory used by video cards, and other such things on your computer, the OS has to be assign those specific addresses to that memory, and it's locked away and can't be seen - effectively making your memory address space smaller. But each user program that runs gets its own 2 GB of virtual memory address space, regardless of the RAM in your machine. There are even programs that can access >2 GB of memory address space, IF you configure Windows to allow it - using the /3GB boot switch. This effectively limits the OS to only 1 GB of virtual memory address space for its own operations, however, causing the operating system to effectively starve if there's a lot of I/O or other demands on the OS itself, so it isn't recommended for ordinary usage. Especially since only specially written programs can take advantage of it.
http://msmvps.com/blogs/xperts64/archive/2008/03/18/32-bit-memory-in-x64-windows.aspx
http://www.brianmadden.com/blogs/br...ws-memory-limit-what-does-it-really-mean.aspx
4GB
address space
http://members.cox.net/slatteryt/RAM.html
the maximum amount of memory that can be supported is 4 GB
Windows XP Professional and Windows Server 2003 Memory Support. The maximum amount of memory that can be supported on Windows XP Professional and Windows Server 2003 is also 4 GB.
http://www.microsoft.com/whdc/system/platform/server/pae/paemem.mspx
However, Microsoft intentionally limited desktop XP and Vista to 4 GB of RAM because many third-party drivers did not work properly when trying to access a memory address above 4 GB. Rather than risk crashes and system problems, Microsoft made it impossible to do.
This issue is compounded by hardware, particularly video boards, that map some of their memory into the 4 GB address space. Windows can do that fine, but in the process it maps some real RAM into the space above 4 GB where it won't be accessed by either applications or the operating system itself. That's why you'll often see Windows use much less than 4 GB RAM on 32-bit XP or Vista, even if you've installed 4 GB of physical memory.
I completely understand why Microsoft instituted the 4-GB limit
http://www.informationweek.com/blog/main/archives/2008/07/windows_memory.html
all 32-bit versions of Vista support up to 4GB of memory
but the actual usable address space will be less than 4GB. The reason for this is that a section of the memory is set aside for memory map interfaces.
Typically, a system with 4GB of RAM will report only 3.5GB of addressable space.
http://compreviews.about.com/od/memory/a/Vista4GB.htm
For 2000/XP/Vista without SP1 the 3gb barrier was seen for the later versions. SP1 now sees Windows report the full amount of memory installed breaking the 3-3.12gb barrier with the 32bit kernel.