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From: dale@amiga.UUCP (Dale Luck)
Newsgroups: net.micro.amiga
Subject: Re: Blitter speed.
Message-ID: <935@amiga.amiga.UUCP>
Date: Mon, 31-Mar-86 22:37:29 EST
Article-I.D.: amiga.935
Posted: Mon Mar 31 22:37:29 1986
Date-Received: Wed, 2-Apr-86 07:44:43 EST
References: <1651@caip.RUTGERS.EDU>
Reply-To: dale@tooter.UUCP (Dale Luck)
Organization: Commodore-Amiga Inc., 983 University Ave #D, Los Gatos CA 95030
Lines: 17

In article <1651@caip.RUTGERS.EDU> OC.TREI@CU20B.COLUMBIA.EDU writes:
>
>     Just how fast is the blitter? How many clock cycles per processed
>word? How do the number of inputs, the presence of an output, and the
>use of modulos and/or barrel shifts effect the speed?

The actual measured speed of the blitter depends on how heavy the memory
buss is already being used. Assuming no bitplanes/sprites/copper the blitter
has nearly 100% access to the buss. With 100% access the blitter can
read/write without any delay.  The it can move data from one point to
another is about 1.8M(words)/second. modulos do not affect timing.
barrel shifting will drop the max bandwidth to 1.3M(words/sec). Each
transfer is read and a write to the memory.  These estimates are
based on a single source and a single destination.
Dale Luck

horizontal lines can be drawn at a max rate of 28Mpixels/sec (b/w).