On Fre, 2002-02-01 at 17:31, Mccary Brady wrote: > Michel Dänzer <[EMAIL PROTECTED]> said: > > > On Fre, 2002-02-01 at 09:56, Mccary Brady wrote: > > > is there a specific reason why some of the rendering routines are > > > performed in software for the ati rage 128 mobility? when > > > xscreensaver loads a gl screen hack on my ibook2, it definitely > > > looks sluggish ... and i want fast gl screen hacks! > > > > Beware that the xscreensaver hacks have a delay between frames, use > > -delay 0 to disable it. The ultimate test to see if there's hardware > > acceleration is the glxgears framerate. :) > > ok, ill be sure to try this when im finished with classes tonite. im not sure > this is the problem though. for example, my intel box w/ a geforce2 has very > nice screen hacks w/o the -delay 0 tweaking.
As should the iBook2. I just mentioned the delay because people tend to wonder why they give rather low framerates by default. > also, quoting http://www.xfree86.org/4.2.0/DRI10.html#42 > <quote> > 10.4.3. Performance and Features > > While PCI Rage 128 based cards are supported, they do not yet support PCI > GART, It's been supported for a long time now. > so they will not perform as well as their AGP counterparts. This is still somewhat true, the difference in performance is around 25%, used to be much worse without PCI GART. > The following OpenGL features are implemented in software and will be slow: > > accumulation buffer operations > stencil, when using a 16bpp screen > Blend subtract, min/max and logic op blend modes > GL_SEPARATE_SPECULAR_COLOR lighting mode > glDrawBuffer(GL_FRONT_AND_BACK) > Using 1D or 3D textures > Using texture borders > </quote> I'm not an OpenGL expert but I think these are rarely used (at least in the average Linux OpenGL app), in particular not in the xscreensaver hacks. > this and various other references seem to indicate that this software > rendering is a substantial bottleneck. Software rendering is dead slow, but if the xscreensaver hacks aren't smooth I suspect there's no hardware rendering involved at all. The X server log and/or LIBGL_VERBOSE=debug might tell why. -- Earthling Michel Dänzer (MrCooper)/ Debian GNU/Linux (powerpc) developer XFree86 and DRI project member / CS student, Free Software enthusiast _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
