Only just noticed my xps m1730 laptop says it's only rocking 3gb ram, tho actually has 4gb. I am aware of win xp 32 bit limitation to 3.5gb, this is not the case i'm running vista and its 3.0gb so less then the 3.5gb limitation anyways. I'm fairly confident that it used to use all the ram, not a total fool and i probably would've have noticed this before. I read somewhere that if your using onboard graphics that can eat into ram, my xps has sli graphics cards but the drivers often crash and they have issues, not sure if the mobo has another onboard output that could be stealing ram when this happens.
So the question is, what (besides OS limitations) causes RAM to show up less then is installed?
I'm using a 64bit OS, that's why i said I'm pretty certain this isn't an OS limitation, (tho running vista whatsoever is probably a limitation) I would dearly love to put win7 back on my laptop but dell doesn't have any support for win7 on this machine and the lack of drivers made it a pain last time i tried that.
I'm thinking tho this is more a hardware issue or GFX card related.
The Dell or any laptop uses RAM for the GPU since most laptop GPU's don't have dedicated RAM it pulls it as Hardware Reserved. I assume you have 2x2GB of RAM so if one were bad then you'd only have <2GB.
To see the values allocated to your GPU boot in to the BIOS, my assumption it's going to b 750~1000 MB.