Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!shelby!decwrl!sgi!msc@ramoth.SGI.COM
From: msc@ramoth.SGI.COM (Mark Callow)
Newsgroups: comp.sys.sgi
Subject: Re: Windows
Message-ID: <32731@sgi.SGI.COM>
Date: 14 May 89 00:30:15 GMT
References: <8905131724.aa08908@CAD.USNA.MIL>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 34

In article <8905131724.aa08908@CAD.USNA.MIL>, dfr@CAD.USNA.MIL ("David F. Rogers") writes:
> Since you asked, I would prefer NOT to have a window system! I resent having to
> use one on the 4d. I hate giving up those cycles. Don't say the window manager,
> any window manager, does not absorb significant cycles. They all do.
> I recently demonstrated how much by running exactly the same B-spline
> Surface Ship Design program on both a 2400T and a 4D/20 side by side. The
> 4D/20 has roughtly 10 times the cpu power and 3-5 times the screen i/o as
> the 2400T, at least according to the specs. The 4D/20 ran VISUALLY slower!
> The more windows you put up the slower it ran. If I didn't need the cpu
> cycles for associated analysis programs, I would go back the the 3000 series.
> Sigh ......

If you put up more windows doing drawing, the system has to do more work
so of course a given application is going to slow down.  Many people like
to run more than one thing at a time and regard being able to do so as an
great advantage.

4Sight has 2 potential impacts on performance: memory and input overhead.

The news server in 4Sight uses around 2 megabytes of memory.  This definitely
causes increased swapping on 8 megabyte systems.

Since many input events are routed through the window server, running the
window system adds some overhead to event delivery.

We have been working on both these issues for release 3.2.  Input overhead
(total system + user cycles) will be not more than 5% of the cpu.  Working
set of the window server will stay below 1.5 megabytes.

4Sight does not introduce any overhead on drawing.  All drawing goes directly
from the GL program to the hardware just as if the window system wasn't there.

--
	-Mark