Wednesday, July 21, 2010

Windows 32 bits using more than 4GB of RAM !!!!

Here is a "nasty" article about how to hack your Windows 7 32 bit to use more than 4GB or RAM.


It looks like MS Windows can use more than 4GB or RAM but MS don't want to sell it that way:
"That 32-bit editions of Windows Vista are limited to 4GB is not because of any technical constraint on 32-bit operating systems. The 32-bit editions of Windows Vista all contain code for using physical memory above 4GB. Microsoft just doesn’t license you to use that code. 
If you want that this should work for you without contrivance, then pester Microsoft for an upgrade of the license data or at least for credible, detailed reasoning of its policy for licensing your use of your computer’s memory in 32-bit Windows Vista. 
Both 32-bit and 64-bit Windows can use all of physical memory, including above 4GB, but a 32-bit Windows application has at most 3GB of linear address space through which to access physical memory.
If you have a 32-bit program that wants more than its 2GB or 3GB, then upgrading to a 64-bit version of that program to run on a 64-bit operating system is your only path ahead. If you’re buying a new computer and new applications, then getting 64-bit Windows and 64-bit applications is obviously the way of the future. Meanwhile, if your concern is only that the system and all your 32-bit applications may together use all your 4GB or more, then keeping your 32-bit operating system would at least be an option for you if Microsoft would provide you with license data to let you use the PAE support that Microsoft has already coded into the product.
Application-level code and even most system-level code is entirely unconcerned and unaffected. Except for the operating system’s memory manager and for the relatively few drivers that work with physical memory addresses, most notably for Direct Memory Access (DMA), no 32-bit software needs any recoding to benefit from a more-than-32-bit physical address space.
If you have exactly 4GB of RAM installed, then getting the kernel to use physical addresses above 4GB will be no benefit to you unless some of your 4GB of RAM is remapped above the 4GB address. Whether this remapping is done at present on your particular machine can be checked by using the separately supplied driver. If it is not done, then whether it can be arranged is an issue of hardware configuration. Check your BIOS Setup, read your chipset manual, or consult your computer’s manufacturer.
If your chipset does not support remapping, then RAM that is overridden for device memory below 4GB will never be seen as usable RAM by 32-bit Windows even with PAE enabled and is just as much lost to you if you install 64-bit Windows.
If you have physical memory above 4GB and wonder how it can be that the PAE kernel does not use that memory, the answer is licensing. The 32-bit code for using memory beyond 4GB is present in Windows Vista as Microsoft supplies it, but Microsoft prepares license values in the registry so that this code never gets to work with any physical addresses above 4GB.
Especially unsatisfactory is that Microsoft says something about its product, and about other people’s products, but uses the licensing mechanism to deny the means to test what’s said.
RAM that is overridden for hardware support is as lost to Windows Vista SP1 as to the original. RAM in excess of the license limits is discarded by Windows Vista SP1 as by the original. Windows Vista SP1 just doesn’t let these losses show as obviously.      "


Prepare to lick your fingers. You will like it:
http://www.geoffchappell.com/viewer.htm?doc=notes/windows/license/memory.htm

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