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Newsgroups: comp.unix.bsd Path: sserve!manuel!munnari.oz.au!spool.mu.edu!umn.edu!csus.edu!netcom.com!hasty From: hasty@netcom.com (Amancio Hasty Jr) Subject: Re: public S3 design (Was: Free software and ... Diamond products) Message-ID: <1992Oct4.154227.15530@netcom.com> Organization: Netcom - Online Communication Services (408 241-9760 guest) References: <BvGoLF.8nn@pix.com> <1992Oct3.055409.17914@gagetalker.com> Date: Sun, 4 Oct 1992 15:42:27 GMT Lines: 111 In article <1992Oct3.055409.17914@gagetalker.com> scotty@gagetalker.com (Scott Turner) writes: >In article <BvGoLF.8nn@pix.com> stripes@pix.com (Josh Osborne) writes: >|> In article <BvCyt0.JG4@immd4.informatik.uni-erlangen.de> Torsten Duwe >(duwe@informatik.uni-erlangen.de) writes: >|> [...] >|> >Doesn't performance depend solely on the main (bus/memory/whatever) clock ? >|> >... would be a bad thing if drawing speed was closely coupled to the pixel >|> >clock. >|> >|> With normal DRAM (i.e., not VRAM, not duel ported RAM) if the shifter needs >|> to output 65 Mega Pixels per second (assuming 8bits per pixel) 65 Mbyte/sec >|> of bandwidth is used to feed the shifter, which is 65Mb/sec you can't use to >|> transfer data to the DRAM. >|> >|> [...] >|> >In my opinion local bus is unnecessary if you have an 'intelligent' SVGA to >|> >give complex commands to. Only memory to screen bitblt is an issue but that >|> >should be solved using more video RAM - hope the '928 is able to address >more >|> >than 1 Meg. >|> >|> Well please optimise copy plane of pixmaps with xor on and have enough RAM >|> that all of xtanks pixmaps can be resident (I think there is over 1M of them >|> once rotated out, if not I know there is over 500K of them). [...] >|> >|> >[...] >|> >>(4) S3 corportation provides a software development kit >|> >Yup! They're very DOS-infected but nice people. >|> >|> I thought they had a windows bias, the 911 isn't very fast unaccel'ed >|> (isn't as fast as, say, the ET4000), and most DOS programs arn't accel'ed. >|> Not that windows is all theat diffrent from DOS... >Interesting discussion guys, but you're both missing the big advantages to >using something like local buss or an S3/8514 card. > >The single biggest thing you need is unbanked access to the video memory. >Next is mouse in hardware. Then comes video refresh rate vs VRAM/DRAM. The 8C911 is not available with DRAM > >Not having to look over your shoulder to make sure you haven't switched >banks or drawn on the cursor make a huge difference in performance. The S3 >chip has an on board mouse and having an 8514 interface it has unbanked >access to the video memory. > >But massive bandwidth to the memory doesn't always pay off. I've benchmarked >the ATI Graphics Ultra against the ATI GraphicsVantage. The Ultra has over >twice the bandwidth of the Vantage and yet is only 20% faster in the windows >benchmarks. > >I did a BLIT port of X11R4 to SysV386 3.2 and using the 82786's on board >mouse hardware almost doubled the speed of the server (using the onboard >drawing engine also gave it a BIG kick in the pants, too bad the damn thing >died, sigh.) > >Western digital was shopping around a chip earlier this year that was designed >specifically to speed up X. It pratically ate X straight (like the 82786) and >thus might be an interesting chip to play around with. > Is the above mentioned chipset the S3? >Scotty Tnks Scotty for the info on the advantages of using the hardware cursor. First off, I found an S3 svga card by Actix which I can set the dot clock values. Actix's telephone number is 408-986-1625. You may also obtain the GraphicsEngine, the S3 card, from Palo Alto Computers. They are located in Palo Alto, Ca. I don't have my dealers number. Palo Alto Computers sells the GraphicsEngine for less than $250, and if you obtain the card from Actix they will sell it for the list price of $300. All technical questions about the GraphicsEngine should go to Actix. The GraphicsEngine comes with 1 MB of VRAM and there is no S3 8C911 DRAM version. Now on the X server side of things, I have modified an 8514/A X server to work with the S3 chipset. The server seems to work and it is fast. For instance moving a window around an releasing the mouse button, the server draws the window as soon as I release the button. The impression that I have is that it feels faster than a Sun Workstation IPX! The major problem that I have is that the server seems to draw half of the characters. When all the major problems with the X server get eliminated, I will be more than happy to post my xbench results. The 8514/A X server was developed under Linux and the S3 X server is being developed under 386bsd. The work to get the GraphicsEngine working started on Tuesday and on Saturday I was enjoying graphics with a resolution of 1024x768 interlaced. I had previously modified the 8514/A server to work with the S3 chipset. The new work was related to initializing the S3 properly,e.g., setting the dot clocks and the Horizontal and Vertical Timing values, etc. My X server uses the extended graphics functions on the S3 and does not use the vga banking. Many thanks to Kevin Martin for providing the 8514/A X server. Enjoy, Amancio Hasty