Well the Max you can install on any 32 Bit system is 4GB. Even then it will only recognize and use 3GB to 3.5GB of the RAM. That doesnt mean that the person who only has 3GB recognize uses a 1GB GFX card though. It doesnt even mean they use a 512MB card either. That is just how 32 Bit OS's work. They are funky when it comes to that much RAM.
I know a person who had his system recognize 3GB and they used 64MB onboard Video.