Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!samsung!rex!ames!pasteur!agate!shelby!msi.umn.edu!noc.MR.NET!gacvx2.gac.edu!gacvx2.gac.edu!scott From: scott@texnext.gac.edu (Scott Hess) Newsgroups: comp.unix.amiga Subject: Re: Adding Symmetric Multiprocessing to Amiga UNI Message-ID: Date: 30 Jan 91 03:30:42 GMT References: <1991Jan29.024542.1@ccvax.iastate.edu> <20668@hydra.gatech.EDU> <994@swrinde.nde.swri.edu> <20708@hydra.gatech.EDU> Organization: Gustavus Adolphus College Lines: 72 Nntp-Posting-Host: texnext.gac.edu In-reply-to: ken@dali.gatech.edu's message of 29 Jan 91 21:17:04 GMTLines: 72 In article <20708@hydra.gatech.EDU> ken@dali.gatech.edu (Ken Seefried iii) writes: Keith Packard (the X Performance Man at MIT) has indicated that the best way to speed up an X server is to put it on a fast processer with good memory bandwidth and direct access to the frame buffer. The worst way is to try and stick it at arms length on some form of co-processor. Bottom line seems to be that if your concern is a fast X server, leave it on the '040. If you offload disk, net and serial traffic from the main CPU, I think you'll see a big win all the way around. 'Course, I'd want to get some empirical data before I bet the farm on it... doug@ctc.contel.com (Doug Whitehead) writes: My embellishment: Hey why not use the 68030 exclusively for an X server! Some folks pay the cost of an AmigaUX just for an X server. This would be a KILLER X window system!!! crs@convex.cl.msu.edu (Charles Severance (System Manager)) writes: Just another idea for use of the spare '030 in the Amiga. There is a lot of CPU wasted to run the bit-mapped graphics display when running X-Windows, open-look, etc. The '030 could run dedicated display software and be sent messages about what is to be displayed. (almost like having the '030 acting like an X-terminal in the same box.) Then the '040 could do the actual work. I suspect that the best solution, that is, if you're considering this, is to put the X server on the _040_. Yes, I know, blasphemy. But, when it comes right down to it, an 030 running application code only (no X server, in other words) could probably keep the 040 running X fairly busy. Put io processing and everything on the '040, too, and the '030 can run unconstrained. Look at the NextDimension (and many other graphics boards for other computers) - an i860 is faster than an '040 for most stuff (though I'm sure it wouldn't run Unix so well :-). Most applications written for graphical environments (X is, arguably, a graphical environment) spend more time drawing graphics than doing calculations. Exceptions? Mandelbrot sets, ray tracing, etc - but those would probably be better run in the background without any window system running (sigh, an '040 and an '030 would be heaven). For those types of programs, the 040 wouldn't be able to keep the 030 running X busy (X is very bitmap-oriented, so would fly through the _display_ of the bitmaps resulting from the calculations, while the calculations wouldn't be helped at all by X). But gosh, the '040 running X alone, 030 running clients would be _slick_. Put the windowmanager on the 040 side (so it's close to those events), and you've got yourself a great machine to sell X with ("now, see how the windows fly across the screen when you move them). From the way it sounds, though, it would probably be better to get the Amiga custom chips working the X. I guess maybe you could do like some of us were thinking of on the NeXTs - we'd get our upgrade board, and leave the current system board in (well, with a couple modified traces). Then, you'd have two completely seperate motherboards, one with an '040, one with an '030, though you'd not be able to run two monitors off of it. How to connect them? Thinwire ethernet . . . While I'll admit that this is not the best solution, it's simple. I don't know if that would work for an Amiga with a coprocessor, unless the coprocessor ignored system memory - something I would be surprised at (would the boards be regular backplane boards or special slot boards? Makes a difference . . .). You never know, though . . . sounds fun either way . . . . -- scott hess scott@gac.edu Independent NeXT Developer GAC Undergrad "Tried anarchy, once. Found it had too many constraints . . ." "Buy `Sweat 'n wit '2 Live Crew'`, a new weight loss program by Richard Simmons . . ."