if you use a 32bit OS it can only address 3GB ram (talking about vista and XP here).
so the graphics card memory would take 1792 of the 3064 (or whatever it is)... leaving you like 1.3GB of ram. plus the page file.
This is interesting. Partly because it's widely considered 100% accurate... and yet for some reason it isn't always.
I've got 4GB of RAM in an XP system. When I had a 512MB 8800GT installed, maximum available RAM was 3.25GB. I pulled the 8800GT and installed a 1GB Radeon 4850, maximum available RAM 3.25GB. Out of interest, I pulled that card too and stuffed in an old 2MB PCI Rage II card... maximum available RAM 3.25GB. PAE extensions are
not enabled.
By the logic of subtracting RAM... I should not be seeing 3.25GB of RAM with the 1GB 4850 installed. It should be at most 3GB, and likely 2.25GB. And yet I am seeing 3.25GB - the same amount as with a 512MB card, or a 2MB card. The system is perfectly stable and happy...
so if i have 4 gig in my system
using xp 32 bit, games are played with only 3 gig?
best thing is to upgrade to 64bit os and the gtx will use all its and system memory?
On paper, a 32-bit OS can only address a maximum of 4GB of memory. That is system RAM and graphics RAM. Conventional wisdom is that running a 32-bit OS with 4GB of RAM means only 3GB is available. Because people were stupid, and couldn't understand this, Microsoft patched Windows Vista 32-bit SP1 to tell people that in 4GB systems there was 4GB installed but only 3GB was 'available'. It saves non-technical people from trying to return the systems they've bought because they "Don't have the right amount of memory" or whatever.
However, Microsoft never went back and did this with XP, so with 4GB of RAM in the system, XP will report anything from 3GB to 3.8GB of available RAM. There is a trick called "physical address extension" that is supposed to fake 48-bit support in a 32-bit OS so that all 4GB of RAM can be addressed separately to the graphics RAM... but it doesn't always work properly and some programs don't like it.
...
If you want to avoid potential headaches... yes, get a 64-bit OS. If you can use XP until October 22nd, or wait until then... you can move to Windows 7 x64.