You'll also need to get a better GFx card, but luckily, with the rapid rise of technology, Geforce 6 series, which are still rather new, have dropped radically into the low $100's (recommend 6600GT+ $120).
Sony has picked the Nvidia RSX, a hot new graphics architecture, and will run it at 550 MHz, which Sony claims is more potent than a pair of GeForce 6800s working in unison.
Nvidia GeForce 8600 GTC - If you are looking for a basic video card that can handle some graphic intensity, but are not a game freak, than this one may be the one to get.
At low settings, a 1.1Ghz - 512MB RAM PC2700 - Geforce 4 4200 ran smooth at around 35 fps, but large scale battles took a tremendous amount of time to render.
Nvidia GeForce 8800 GTX or GTS - This video card is one of the best if you are a heavy PC gamer who plays titles with high-intensive graphics.
A midrange budget Geforce 6800 with 128MB RAM will do the job just fine and often costs less than $180 on internet retail stores.
It also comes with an nVidia GeForce 8600 GTS graphics card, though there are options to choose one of several 8800 models.
The PS3 uses the Nvidia RSX, which Sony says is more powerful than two GeForce 6800 strapped together.
Nvidia GeForce 7950 GT -Another good video card that will give your games and applications a boost.
Geforce 4Ti's are not supported and are now closer to becoming obsolete as technology improves.