Yes, it could, unless you're running a 64-bit OS and processor. Most computers, which are 32-bit, have a total or 4 GB of addressable memory space, which includes video memory, sound card memory (if you actually still use one) and system RAM. Therefore, if you put in a 2GB video card, you can't make use more than 2 GB of system RAM.
That's not entirely accurate. PAE makes it possible to address 4+ GB of addresses on a 32-bit system, so long as your operating system supports it fully. AFAIK both Linux and BSD happily do, and certain Windows versions also support it.
As the evidence for this has accumulated, several fairly contorted and unsatisfying efforts have been aimed at solving the puzzle. Cramer has proposed an explanation that doesn't violate the speed of light but does kind of mess with the traditional concept of time.
The University of California Statistics Department; where mean is normal, and deviation standard.