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Re: FrameThrower vs CAD Buffer II for XL1200 color graphics?
Date: Thu, 15 Nov 90 09:45:05 -0500
Date: Wed, 14 Nov 90 11:06 PST
Subject: FrameThrower vs CAD Buffer II for XL1200 color graphics?
To: Marty Hall <email@example.com>, firstname.lastname@example.org
Date: Wed, 14 Nov 90 09:36:39 -0500
From: email@example.com (Marty Hall)
Does anyone have any experience in the performance advantages of the
FrameThrower board vs the regular CAD Buffer II for normal Symbolics
color graphics on an XL1200? By "normal" I am talking about using functions
in the Symbolics color system or just graphics:draw-xxx with :color
arguments, not anything with any of the S-products, HDTV, etc. We are
looking to speed up things like reopening windows, popping up menus,
drawing/animating simple graphics, etc, that take place on the color screen.
Ie the FrameThrower board is designed to do much more than act as a
color graphics accelerator, but if it were used in that role, does
anyone know what kind of a performance benefit there would be?
Our local sales rep thought "significant" (or were they thinking of
the price? :-), but was a bit fuzzy.
Just by having a 1200 things get faster by a factor of 3, so any overhead-dominated
operations (such as drawing zillions of small things) get faster by 3.
It may be that in general an XL1200 is 3 times an XL400. But, it has
been our observation that drawing lines on a color XL400 in genera 8.0
is twice as SLOW as drawing in color on a 3640. So the performance
advantage may only be about 1.5.
Line drawing, especially in color, was one of the places where Ivories
looked poor. Raw line drawing speed got about twice faster in 8.0.1.
Other than that specific, you're correct to observe that raw speed of
color drawing on Ivory machines was significantly slower than on 36xx,
due to limitations of the color hardware available on Ivories. However,
fixed overhead per operation is the majority of the cost in most real
applications, so I'd generally stick to 3 as the starting guestimate.
Of course, the speed of operations problem is fixed, and then some, by