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Xref: sserve comp.os.386bsd.questions:6501 comp.windows.x:60576 Newsgroups: comp.os.386bsd.questions,comp.windows.x Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!swrinde!cs.utexas.edu!uunet!virtech!dwex From: dwex@aib.com (David E. Wexelblat) Subject: Re: XFree86 2.0 Experiences Message-ID: <CG044M.185@aib.com> Organization: AIB Software, Inc. References: <CFtHwE.5qK@festival.ed.ac.uk> <CFvyn1.732@aib.com> <CFxApF.C01@festival.ed.ac.uk> Date: Fri, 5 Nov 1993 04:21:57 GMT Lines: 69 In article <CFxApF.C01@festival.ed.ac.uk> richard@castle.ed.ac.uk (Richard Tobin) writes: >In article <CFvyn1.732@aib.com> dwex@aib.com (David E. Wexelblat) writes: >>xengine is an irrelevent benchmark. > >Well, it certainly isn't a good benchmark, it was just what I had to hand. >I was just interested to know if there were some things the S3 server >was known to be slow at. Lots of them. We'll worry about them later. > >>Your ET4000 may be running >>with 0 wait states and your S3 with 1 wait state. > >This could be true; I'll look into it. > >>>(3) The 16 colour server runs much slower than the 256 colour version. >> >>No kidding. Guarenteed. > >Is that inevitable or will it get better in future releases? Naively >I'd expect it to be twice as fast, since it has only half as many bits >to push, but no doubt the incredibly stupid VGA interface more than >cancels this out. > Well, look at it this way. Assuming no raster-op and no planemask (i.e the vast majority of the cases), setting a pixel in 8bpp means loading a byte. Setting a pixel at 1bpp means read a byte, modify the bit, write the byte (of course, this gets optimized when spans are 8 or more pixels long). In dumb-VGA 4bpp mode, you have to do this read-modify-write 4 times. Again, a lot of optimization gets done, so it's never worst-case, but the average case is far worse for 4bpp. You can see some of this dramatically if you run xbench on mono and 8bpp. You will see that mono is way faster for fills/copies, but slower for most everything else. >>>(4) The mono server doesn't work at all. > >>Run it in "generic" mode. > >Ok, I'll try that. > >>Be happy with your S3 board. > >I am. Unfortunately it's not mine :-( So buy one. They don't cost much. > >Thanks for your help. > >-- Richard >-- >"Beat your ploughshares into swords and your pruninghooks into spears" >(Joel 3:10) -- David Wexelblat <dwex@aib.com> (703) 430-9247 Fax: (703) 450-4560 AIB Software, Inc., 46030 Manekin Plaza, Suite 160, Dulles, VA 20166 Formerly Virtual Technologies, Inc. Mail regarding XFree86 should be sent to <xfree86@physics.su.oz.au> "Ooh, are you feelin' satisfied? Come on, let us give your mind a ride." -- Boston, "Feelin' Satisfied"