Banned because valentine's day is approaching, which means it's time for people to become even more hyperemotional and frustratingly stupid than usual.
Valentine's day is annoying, isnt it?
banned for thinking i'm emotional
Whoa, is this another Code Geass fan? Or is this you Xer07? 
The limit of 32 bit OS is yes 3.25 but Win takes up 1.25 leaving 2 leftover for other apps.
Are you for real? Windows doesnt take up 1.25 GB of ram, thats ridiculous.
If you're talking about Win 7, then it takes up a lot of ram by default, but definitely NOT 1.25 GB. I'd say about 600-700 MB on average, depending on drivers, programs, startup apps, etc.
If you're talking about Win XP, then its 200-350 MB, again depending on installed programs.
On a side note, if you have Win 7 and chose the 32-bit version of it, then you're a noob, lol. There's no reason to not go for 64-bit, its only the sensible thing to do.
On the other hand, if you're the type who cant give up their loved Win XP, then 32-bit is the way to go, since 64-bit suffer from some compatibility issues, as far as I know.
In short, NO, Windows would never take up 1.25 GB of ram for everything else besides the game, unless you're running many other programs at the same time, filling your taskbar with unnecessary apps while playing SoaSE (in which case you're kinda stupid).
Sins loads everything (and I do mean everything) into the RAM system in order to keep things running smoothly at all times and not have to worry about reloading every time you rebuild a new ship type or expand out from a single planet to looking at 20 stars. The downside of this is that while the first two games (the Original and Entrenchment expansion) did okay and not cause too many issues (mods were another issue) the last expansion, Diplomacy, broke the game past the 2 gig limit. There were some things that helped (Sins Optimization Mod and LAA) but in the end you also had the CPU issues (tons of units) as well and the game was failing bad after about an hour or two. So the Developers finally figured out a way to streamline it all and get the game working again.
Like I already said, there isnt any 2 GB limit, unless you have 2.5 GB of system ram, or something. With 3 GB of Ram installed, and your Win 7 taking up 650 MB by default, then you'd be stuck with 2.35 GB of available ram, without your system using any virtual memory (Swap space). Just an example of course.
For the last time, if someone is dumb enough to choose the 32-bit version of Win 7, then they suck, lolz. If you want 32 bit, go for Win XP. If you want 64-bit, then Win 7 is a WIN 
Win XP can handle the 32-bit memory limit, Win 7 CANNOT.
Now, as far as I understand, and looking at the requirements of the game, SoaSE must be somewhat CPU limited, as it doesnt support PhysX, - its kind of an AMD supported game (its not The Way its Meant to be Played, aka Nvidia), - so all these particles, explosions (if any), debris, etc is a task left for the CPU to handle, and not the GPU. This is kinda stupid, as GPU physics hardware acceleration relieves a lot of 'pressure' from the CPU.
Also, tons of units on 1 frame, at the same time, usually means that a lot of frame buffer (RAM) from the graphics card is required for smooth frame rates (depending on your resolution of course) as well. It also means that a lot of stream processors/CUDA cores help the GPU somewhat, but at the end of the day, if there is no physics GPU acceleration, a lot of the burden always falls on the CPU.
Lastly, if the game is properly optimized, physics or not, powerful systems or not, you can achieve desirable framerates even on an average gamer's PC.
Banned for making me say all that.
