How to calculate the needed amount of video RAM

[Frisbee]

Hello people;

I have a question:
What is the formula with which you can calculate the minimum necessary amount of video RAM to display a certain screen resolution and color depth?

For instance, I seem to remember that for a resolution of 640x480 and 16-bit color depth, you need 1Mb of video RAM, that is: for a 2D screen.

So: what is this formula to calculate the nesessery amount of video RAM for a certain 2D screen resolution?
And is the formula for 3D images any different?

Many thanks!
Carl
Brussels

 

[Col_Kiwi]

(((WxHxC)/8)/1024)/1024)

W = Screen width in pixels
H = Screen height in pixels
C = color depth in bits per pixel

ex.
640x480x16 = 586KB

-Col.Kiwi

 

[chuck232]

There's more than just that I think. For example playing UT2003 in max settings (but no aniso or AA) at even 1280x1024, it takes up much more than 64MB of VRAM...

...And all the King's horses and all the King's men couldn't put my computer back together again...

 

[Frisbee]

You are right.
But I think that the formula stated above is for 2D-screens only.

So, does anybody know if there is a "general formula" with which you can calculate the necessary amount of video RAM for 3D at any given resolution/color depth combination?
So, not for 2D, but for 3D.

Many thanks;
Carl
Brussels, Belgium