Path: utzoo!attcan!uunet!lll-winken!arisia!sgi!shinobu!odin!horus.esd.sgi.com!thant
From: thant@horus.esd.sgi.com (Thant Tessman)
Newsgroups: comp.sys.sgi
Subject: Re: Multiprocessor IRIS m/cs
Keywords: speedup parallel graphics
Message-ID: <2793@odin.SGI.COM>
Date: 13 Jan 90 01:04:30 GMT
References: <11299@cs.yale.edu>
Sender: news@odin.SGI.COM
Reply-To: thant@horus.esd.sgi.com (Thant Tessman)
Organization: Silicon Graphics, Inc.
Lines: 19

In article <11299@cs.yale.edu>, kankaria-praveen@CS.Yale.EDU (Praveen
Kankaria) writes:
> 
>   Is it true that one processor is dedicated to graphics on the
multiprocessor
>   IRIS machines ?  The speedups we got for some parallel programs on a
4 processor
>   machine suggest that.
> 

I'm not the person to answer this, but I'll try.

There is no one processor dedicated to graphics.  Any of them can send
graphics down the pipe.  However, only one processor *per process*
can send graphics to the pipe.  Only the original thread owns the 
graphics context.  This is probably the cause of the results you are
getting.

thant