Path: utzoo!dptcdc!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!cs.utexas.edu!uunet!dg!rec
From: rec@dg.dg.com (Robert Cousins)
Newsgroups: comp.arch
Subject: Re: to graphics processor or not to graphics processor
Keywords: graphics processor
Message-ID: <130@dg.dg.com>
Date: 17 Apr 89 13:06:00 GMT
References: <28930@apple.Apple.COM>
Reply-To: rec@dg.UUCP (Robert Cousins)
Distribution: usa
Organization: Data General, Westboro, MA.
Lines: 40

In article <28930@apple.Apple.COM> jrg@Apple.COM (John R. Galloway) writes:
>  Now I see there is another example.  The Data General Maverick 88000 based
>workstation uses an NEC 72120 (whatever that is) for mono and a custom
>gate array (whatever_that_is**2) for color.  Any DG engineers out there who
>would like to discuss why they chose to do so?  
>
>apple!jrg	John R. Galloway, Jr.       contract programmer, San Jose, Ca
>
>These are my views, NOT Apple's, I am a GUEST here, not an employee!!

Yes, we choose to use graphics coprocessors on our AViiON line of workstations
for several reasons:
	1.	Lawrence's Law:  There are only two ways to speed up a
		computer:  build it out of faster parts or do more than 
		one thing at a time.  A coprocessor allows you to do more
		than one thing at a time.
	2.	Sure the 88000 is fast and can do graphics operations very
		quickly (faster than most graphics coprocessors in fact).
		However, more and more workstation applications are of the
		form "compute, draw, compute, draw . . . ." where the 
		parallelism gain is substantial if draw and compute can
		be overlapped.
	3.	Most previous graphics architectures assume relatively
		weak CPUs and relatively more powerful graphics hardware			or the extreme opposite of relatively powerful CPUs and
		totally brain damaged graphics hardware (dumb frame buffer).
		The newer, faster CPUs like the 88100 make intermediate
		balancing easy.  
	4.	Cost.  A proper choice of graphics subsystems allows not
		only the cost to be reduced but also the power and space --
		all of which has impact on the retail cost.
I think it safe to say that we did a pretty good job.  There aren't any
machines that I know of that can match the AViiON line in power (CPU or
graphics) in the price range.

Robert Cousins
Department Manager, 
Workstation Development,
Data General Corporation

Speaking for myself alone.