Sender:	crough45 AT amc DOT de
Date:	Thu, 10 Apr 1997 09:50:35 +0100
From:	Chris Croughton <crough45 AT amc DOT de>
Mime-Version:	1.0
To:	peter AT atmosp DOT physics DOT utoronto DOT ca
Cc:	djgpp AT delorie DOT com
Subject:	Re: Interrupts (Hardware)
Message-Id:	<97Apr10.104800gmt+0100.21890@internet01.amc.de>

Peter Berdeklis wrote:

>The graphics won't affect interrupt latency at all.  The graphics code is 
>just interrupted.  In fact, most graphics code is slow not because of the 
>CPU time it uses but because the bus is slow (ray tracing is an obvious 
>exception).

If the bus is slow won't that affect the interrupt latency?  Surely an
instruction can't finish until it's accessed the bus (as far as I know
the cache doesn't do video memory - at least on my machine it seems that
video accesses are the same speed with and without cache).

And why is ray tracing different?  Is it because of the difference 
between slow video RAM and the faster RAM used by the ray tracing
algorithms?

(I'm not a graphics programmer, I'm interested in learning about
these things.)

Chris

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