Graphics performance of Sun 386i?

[Mike Thompson]

Greetings,

This month "Unix Review" published a review of the Sun 386i which gave an
overall rating of average.  Since I use a Sun 386i as a software
development platform I have to agree with many of the conclusions reached
in the review.  What surprised me most however is how slow the graphics
really are on the Sun 386i.  With this being my first experience with an
engineering workstation I was somewhat disappionted by how sluggish the
feel of the graphical interface is.  I am using a Sun 386i/250 which runs
at 25 MHz, has 8 Megs of RAM, and has the 1152x900 pixel color display.
Under both SunView and the X Windows System R3 the display exhibits an
irritating sluggishness.  As a measure of graphics performance, "Unix
Review" gave the following performance values:

	 	    Sun386i   Sun-3/160   HP 9000/360   HP 9000/360
		    CGI Lib.  CGI Lib.   Starbase Lib.   X Windows

Medim-Length
Diagonal Line	      193       370         2976           376

Medium-Sized
Filled Square          18        85           82           202

Medium-Sized
Unfilled-Square	        4         2           40            50

Unfilled Medium
100-sided Polygon      56        46          198            73

Grafstone Rating      600      2051         7566          7610

My question is: Why is the 386i so slow in graphics when non-graphical
programs execute at a speed in keeping with its fast CPU?  I know that the
video buffer memory has an access cycle of 280 nanoseconds.  This seems to
be very long.  Is the hardware architecture the reason for the poor
graphics performance on the Sun 386i or does it lie in the software?
Perhaps Sun is trying to pull an IBMish move by handicapping the 386i so
as not to cut into the sales of Sun 3's.

I hope that someone can shed some light on this subject for me.  Until
then, I will just keep looking for improved X Windows server software.

Mike Thompson

Michael P. Thompson                      FOCUS Semiconductor Systems, Inc.
net: (sun!daver!mfgfoc!mike)             570 Maude Court
att: (408) 738-0600 ext 370              Sunnyvale, CA  94086 USA