On Mon, 01 Aug 2005 18:14:16 -0400, Josh wrote in message <[EMAIL PROTECTED]>:
> Arnt Karlsen wrote: > > > ..pass, what I learned from my own research on gpu's before buying > > an ATI 9250 clone, is ATI are "native 24bpp" and "24bpp only", where > > Nvidia is "1x32bpp or 2x16bpp", suggesting "ATI would suck at 16bpp > > doing less than 3x8bpp" and "at 32bpp not being able to see or make > > any use of the top 8 bits." > > My understanding of Nvidea is "their cards should work better at > > 32bpp and 16bpp than at 24bpp, because 24bpp wastes half a 16bpp > > engine." > > > > > > >From what I understand, 24bpp is the same amount of data as 32bpp. It > just signifies that there is a separate alpha channel. Since this is > not strictly 'color' the last 8 alpha bits are not counted in the > color depth. ..yes, but does this impact 32bpp performance relative to 24bpp and "not" 24bpp relative to 16bpp like it "should" on ATI's and "should not" on Nvidea and vice versa? > Still, each pixel takes up 32 bits of memory. ..my understanding is ATI cannot do 32bpp math at all, their gpus are "24bpp only", while Nvidea gpus does both 16bpp and 32bpp "but not 24bpp." Strategic gpu HW design choises made a decade or so back. > ATI cards do 16bpp just the same as all the other cards, 16 bits of > color and nothing else. (red and blue get 5bpp, green I think is the > one that gets 6bpp) ..true, at the same speed as they will do 24bpp, 15bpp and possibly also 8bpp, I doubt ATI gpu's has a 3x8bpp mode, Nvidea however talks about a 2x16bpp and an 1x32bpp mode. -- ..med vennlig hilsen = with Kind Regards from Arnt... ;o) ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
