128-bit color... but where?

I just got a Radeon X800 Pro, and it is supposed to have 128-bit, 64-bit & 32-bit per pixel floating point color formats. Isn't this the color quality setting that is in Display Properties Settings? If so, how come 32-bit color, my old maximum, is still the highest choice?

 

I could be wrong, but I believe those are what the card renders, not the actual display settings.

 

i believe the bit-color formats are for texture sampling or something like that (to make the shades look smooth and stuff) rather than for normal day-day use. But really, 16.7million colors is enough, considering webpages support only up to that, and i don't think the human eye can discern that many shades anyhow.

 

Thanks, I was worried that something was wrong, lol.