These technical concepts are better explained in the given links below:

http://en.wikipedia.org/wiki/Stream_processing

http://en.wikipedia.org/wiki/Graphics_card

Rules of thumb on buying a laptop with the consideration for gaming:

1) If you don't play high-end games which require a dedicated video memory 256MB or above and you don't have a lot of budget, then choose a dedicated graphics support with 128MB dedicated memory (like Nvidia 8400M GS which can turbo-cached to its maximum 256MB taken from system memory; in my opinion, it will slow down bit the game FPS on scenes with a high polygon count like the open-area/forest environment in Crysis game). Otherwise, choose a better dedicated graphics support.

2) If you don't play high-end games or don't play games at all, an integrated graphics card support is sufficient.

This post has been edited by eclectice: Jun 4 2008, 05:42 PM

Yes, 256MB dedicated video memory is sufficient to play Crysis (High setting is possible with certain parameters turned off) and NFS Pro-street (High setting)