Re: [Dri-devel] 16/24bpp throughput (was: bios options for agp4x w/Abit VP6 mobo?)

[Michel <mic...@ii...>]

Alexander Stohr wrote:
> 
> > Now, why would 16bpp get a whopping %50 higher fps in gears than
> > 24/32bpp?
> >
> > 16bpp: ~1300fps
> > 24bpp: ~900fps
> >
> > Is this showing what I think it is--a perfect example of being
> > through-put bound (50% more bytes to push)?
> 
> 2 bytes/pixel * 1300 fps = 2600 bytes/s * frames/pixel
> 3 bytes/pixel *  900 fps = 2700 bytes/s * frames/pixel
> 
> I have to assume that your image is fill rate limited,
> because the transfer rate values are rather equal.

Except depth 24 is 32 bpp, so it's

4 bytes/pixel *  900 fps = 3600 bytes/s * frames/pixel

Probably 16 bit is CPU bound and 32 bit fillrate bound?


PS: Who set the the list up to set the Reply To: header to the list address?
It's considered harmful.

-- 
Earthling Michel Dänzer (MrCooper)    \   Debian GNU/Linux (powerpc) developer
CS student, Free Software enthusiast   \        XFree86 and DRI project member