enable LAA

Large Address Aware Enabler for FO3

check http://fallout3.nexusmods.com/mods/6510

Background info:

Regardless of the amount of physical memory in your system, Windows uses a virtual address space of 4 GB, with 2 GB allocated to user-mode processes (for example, applications) and 2 GB allocated to kernel-mode processes (for example, the operating system and kernel-mode drivers).

On systems that have 1 GB or more of physical memory, these two startup switches (see below), can be used to allocate more memory to applications (3 GB) and less memory to the operating system (1 GB). This additional virtual address space helps reduce the amount of memory fragmentation in the virtual address space of the Exchange information store process.

So, what does this mean? Well...

* Fallout 3 (WITHOUT the 3gb switch and NOT large Address Aware) on 32-bit platforms can address up to only 2 GB.

* Fallout 3 with the /LARGEADDRESSAWARE:YES linker flag on 32-bit Windows XP with the special /3gb * boot option can address up to 3 GB, ie an extra 1GB.(This however, limits the kernel to only 1 GB which may cause some drivers and/or services to fail- but not so much a problem with XP than Vista 32bit).

* Fallout 3 with the /LARGEADDRESSAWARE:YES linker flag on 32-bit versions of Windows Vista, can address memory up to the number specified by the boot configuration data (BCD) element "IncreaseUserVa". IncreaseUserVa can have a value ranging from 2048, the default, to 3072 (which matches the amount of memory configured by the /3gb boot option on Windows XP). I advise using IncreaseUserVa 2900.

(The remainder of 4 GB is allocated to the kernel and can result in failing driver and service configurations. This issue has since been addressed by microsoft via OS updates)

* Fallout 3 on 64-bit platforms can address up to 2 GB, or up to 4 GB with the /LARGEADDRESSAWARE:YES linker flag. So, 64-bit processors provide a huge leap in the amount of physical and virtual memory that can be addressed.