Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!zephyr.ens.tek.com!tekig5!wayneck
From: wayneck@tekig5.PEN.TEK.COM (Wayne Knapp)
Newsgroups: comp.sys.amiga
Subject: Re: A new Amiga...
Message-ID: <5390@tekig5.PEN.TEK.COM>
Date: 16 Jan 90 03:07:51 GMT
References: <4144@wehi.dn.mu.oz> <1051@sdrc.UUCP>
Organization: Tektronix Inc., Beaverton, Or.
Lines: 33

In article <1051@sdrc.UUCP>, evgabb@sdrc.UUCP (Rob Gabbard) writes:
> With the Amiga's custom graphics chips the CPU is freed up to do other things
> while in the PC/Mac world the CPU is all too often bogged down processing the
> graphics operations. That is why the 68000-based Amiga 1000 can still outperform
> a '486 VGA box on similiar graphics operations. I'm sure there are graphics
> co-processor boards that take alot of this burden off the Intel/Mac but compare
> the $$$$ to an Amiga.


Two things:

1. $$$$ to Amiga to pc clone and the Amiga loses on hardware costs, 
   which is the first thing most people see.

2. The amount of help the Amiga co-processor chips give can be very limited.
   They don't help while doing things like drawing a circle or changing
   the color of a pixel.  Many things are done by the 68000 in the Amiga
   also.  This is why I contend that the major bottleneck in the Amiga
   is the chip RAM bandwidth.  Note that a cheap pc clone and VGA com-
   bination can also have a horrible bottleneck.  I've seen over 20 
   wait states per VGA access.  

   Now there are better things coming on the Amiga so I'll change my tune
   when I see them.  However on the pc end it is not too hard to get
   a 340x0 based card that allows one to do real co-processing when it
   comes to graphics.  It even has a C compiler for it.  (Maybe someday
   Commodore will release Rich Miner's 34010 based board!)  Anyway you
   could program the 34010 (given enough RAM) to say rotate the current
   screen image by 1 degree.  This could happen with a sinlge command
   from the processor.  Now that is co-processing!

                                                    Wayne Knapp