I realize that a P4 2.5/400 with 1GB RDRAM (Rambus) is not terribly fast
anymore, but I'm wondering just how "bad" it is for modern games like Doom3,
and how much difference I'll get going to a better videocard. Will I get
much more going from a GF4 Ti4600 to a 6800GT on this system, or am I so CPU
limited that I won't notice much difference other than having access to
higher resolutions? I've tried to find comparisons that might give
information on this, but I've yet to see comparisons showing these cards on
a CPU of this speed, so I'm unclear what to expect.

To upgrade to a faster CPU, I'd have to get a new motherboard, and new
memory as well, which is a fairly large expense. A 6800GT, on the other
hand, is an easy upgrade that's not as expensive. Will a 6800GT breath a
little more life into this system, allowing me to hold off on a full system
upgrade? On one hand I realize that a new system will be faster, but if
just the graphics card will help to some extent for the time being, it would
be nice to wait a bit longer to upgrade the rest of the system. I figure
that a 6800GT will still be decent card for a while, so when I DO upgrade
the rest of the system, I won't need a new graphics card.

Thanks for any opinions on this,

Larry