[CentOS] Centos laptop:: video cards

[Mark Tinberg]

> Valeri Galtsev <galtsev at kicp.uchicago.edu>

On Sun, October 5, 2014 3:02 am, John R Pierce wrote:

> > the modern CPUs with integrated graphcis controllers such as the Intel
> > HD4500 stuff is excellent,

>John, I would respectfully disagree. The bad thing about "shared" memory
>video cards is fundamental in the architecture. They use as video RAM a
>portion of main RAM, that means they place the video traffic (30, or 60,
>50 25 frames per second multiplied by number of pixels worth) onto memory
>bus. This traffic has nothing to do with anything but the screen and just
>doesn't belong there. It is logically independent on anything and should
>be kept separate from memory bus - physically.

I don't think that the shared memory integrated cards work that way, the video output has dedicated frame buffer memory so that every screen refresh doesn't go over the main memory bus, what goes over the main bus are all of the graphical assets and commands used to compose the final image, which often need to be shared with the main CPU anyway.

—
Mark Tinberg
mark.tinberg at wisc.edu