On Wed, 3 Apr 2002, Raystonn wrote: > A GeForce 3 produces about 88 million triangles/second maximum. Now take a > 3GHz Pentium 4, just a few months down the road.
So you are comparing a 2 generations old GPU with a CPU that won't exist until the GPU's have cycled through at least one more generation. OK - that's fair....NOT! You should be comparing a 2GHz PIV with a GeForce 4 Ti 4600. > It has available 3 billion > clocks each second. This allows about 34 clocks per triangle. With a > properly optimized algorithm, using SSE and SSE2 to work on a tile at a > time, this can be achieved. Show me! I don't believe you can rotate/translate/perspect/backface-cull/ light (with 8 light sources please)/clip (include two user clip planes and six system planes)/texgen, and render several dozen multi-textured, fogged, zbuffered and antialiased pixels - all in 34 clocks. I want to see the program that can do this - render a complete polygon from 'glBegin...glEnd' to pixels in the frame buffer in 34 Pentium clock ticks. Now add in multitexture and vertex/pixel-shader programmability and the full richness of OpenGL per-pixel functionality. > What the main processor lacks in physical > resources it can make up with a higher clockspeed. I believe the GeForce > 4Ti is at 300MHz now, is it not? Dunno - but it has internal pipelining so that many operations happen in parallel. In a GPU you can be calculating perspective for one vertex while clipping the previous one and lighting the one before that. You only have to have a 10 stage pipeline and you have an effective 3GHz operation rate - I'd bet that modern GPU's have at least 100 pipeline stages. > Fillrate is still an issue, but will > become less of one as time goes by. Memory bandwidth is ever increasing. See my previous explanation of why this is so far from the truth. In summary: Fillrate is becoming *MORE* of an issue - and memory bandwidth is increasing *painfully* slowly compared to the rest of the system. > Use a scene-capture algorithm and you reduce the required fillrate > dramatically. But if those algorithms are practical for modern application software (HINT: They aren't) then GPU's will evolve to do that too. I've built machines with "scene-capture" (look here: http://www.sjbaker.org/steve/personal/stargazer.html ...that's a screen capture machine). In any case, for 'modern' polygon sizes, the best of these technologies only improve fill rates by a factor of between 2 and 4. Software has to go at least 100 times faster to catch hardware fill rates. ---- Steve Baker (817)619-2657 (Vox/Vox-Mail) L3Com/Link Simulation & Training (817)619-2466 (Fax) Work: [EMAIL PROTECTED] http://www.link.com Home: [EMAIL PROTECTED] http://www.sjbaker.org _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
