cjrgreen: PAE is pretty worthless on Windows XP, because 32-bit XP won't address more than 4GB RAM even with PAE. The 3.58 GB you see is 4GB less the address space that XP can't use for memory because it's occupied by devices.

The 2GB of address space that a game on 32-bit Windows normally gets to use does not include VRAM. The game's graphics resources, which may be extensive, live in VRAM to the extent that the game is able to keep them there. The 2GB holds things like code, the state of the game in progress, resources that are going to be staged to the graphics card, things like that.

One thing not mentioned in the previous discussion is that applications that are to be Large Address Aware (allowing them to address up to 3GB on 32-bit OS and 4GB on 64-bit) must be well coded so that they are "32-bit clean". Code that commingles addresses and signed integers is the sort of code that breaks that rule. Good programmers shouldn't be writing bad code like that, but sometimes they do anyway.

hedwards: Interesting. This is something that I wish I would have known before I bought the RAM for the computer I'm using. The documentation that MS puts out is really, really bad. PAE on other platforms actually permits one to use more than 4GB of RAM, even though it is a bit limited.

Psyringe: ...