X8R8G8B8 - a few questions, if I may...

[Neeyik]

Okay, this has been bugging me for ages now and it's getting on my nerves. What does the X in X8R8G8B8 refer to? How and why is this surface format different to A8R8G8B8, apart from the obvious alpha channel? Under what circumstances, must one use a X8R8G8B8 format?

Many thanks in advance to all and sundry... 8)

 

[Xmas]

The X reallly means '8 bits are not used'. On most (if not all) cards there is no difference to A8R8G8B8, but it would be possible that a chip only uses 24 bits per pixel.

 

[rubank]

Oh, I thought the X was the "nvidia factor" that converts the format to 12 bits...

 

[K.I.L.E.R]

Oh, I thought the X was the "nvidia factor" that converts the format to 12 bits...

DOn't you mean to 2 bits?