Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!sgi!gavin@krypton.SGI.COM
From: gavin@krypton.SGI.COM (Gavin Bell)
Newsgroups: comp.sys.sgi
Subject: Re:  Personal IRIS benchmarks
Keywords: benchmark, polygons
Message-ID: <26596@sgi.SGI.COM>
Date: 10 Feb 89 17:34:09 GMT
References: <8902091617.AA23739@aero4.larc.nasa.gov>
Sender: daemon@sgi.SGI.COM
Reply-To: gavin@krypton.UUCP (Gavin Bell)
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 24

We quote 5,900 Z-buffered, Gouraud shaded, 4 sided 100x100 independent
polygons per second on the Personal Iris.  The 100,000 polygons/second
figure you heard is for the GTX products.

Will you get 5,900 polygons per second in your application?  Not if:
1) You spend any time computing the polygons, or spend any time
	re-organizing the vertex data to match the v() commands.
2) You spend any time clearing your window or z-buffer (remember, it
	takes ~10 microseconds to clear the screen, so at 30 frames/second
	~20 percent of your time is spent just clearing the	framebuffer).
3) You have big polygons (bigger than 10 by 10 pixels).
4) You use the old drawing commands.
5) You draw few polygons in double-buffered mode.  Worst case is
	drawing one polygon, then swapping buffers-- the swapbuffers()
	command has to wait for the vertical retrace of the monitor you
	are using, so you will get only ~60 polygons/second.

The benchmark used to get the 5,900 poly/sec number is, of course,
nowhere close to a real application.  It is single-buffered, never
clears the framebuffer or z-buffer, and has almost no CPU overhead,
and draws only 100 pixel polygons.  But it does give you an idea of
maximum drawing speed.

--gavin (gavin@sgi.com)