View Full Version : Large Address Aware

01-03-2012, 07:03 PM
After seeing this linked today in the comments on RPS I thought it would be a good idea to have it posted in the tech forums for future reference.


Essentially it tries to make a 32 bit executable capable of accessing more than 2 gigs of RAM. Instructions and the like can be found in the link.

05-03-2012, 05:20 PM
I'm almost positive that Win7 32-bit can use a maximum of 3.25GB of installed RAM out of the gate, not just 2GB. I'm running Win7 32-bit on a laptop with 3GB of physical RAM installed and Win7 shows 3.00GB available.

Also, I believe a more useful method of using more physical RAM is the use of PAE (Physical Address Extension) with a relatively simple Windows setting modification. According to this Windows Dev Center page (http://msdn.microsoft.com/en-us/library/windows/desktop/aa366796(v=vs.85).aspx), PAE allows 32-bit versions of Windows to "access more than 4 GB of physical memory," though it doesn't say what the limit is.

05-03-2012, 07:00 PM
It's not about the amount of memory available to the OS, it's about the amount of memory available to an application which is different. Of course, there aren't may applications that need that much memory, but thrid party texture packs for some games (eg FakeFactory for HL2, or some Skyrm mods) do.

Also, the maximum addressable memory space on an x86 based 32-bit systems is 4 gigs, (1 byte per address, 2^32 addresses). However, this includes all addressable memory - some address space is used for graphics card, some for input buffers, etc, which normally brings the amount of main memory available to the OS down to the 3-3.75 gb range.

07-03-2012, 06:00 AM
But isn't there a direct correlation between what the OS can see and what an application can use? If my OS only has access to 3.5GB of RAM, isn't it impossible for any application running within the OS to access beyond that amount? Apparently that isn't a two-way street though, so I guess even if a 32-bit OS can see 6GB of RAM there's no way for any single process to use more than 3.xGB of RAM without some other modification.

That seems to be where Address Windowing Extensions comes into play, which is mentioned on the same Dev Center page linked above, with a specific page for AWE found here (http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html). By the way, for some reason those two pages are taking quite a long time to load right now, but with enough time and/or tries they will eventually load. I guess MS's MSDN site is taking a beating right now for some reason.