Path: utzoo!attcan!uunet!samsung!usc!zaphod.mps.ohio-state.edu!wuarchive!mit-eddie!rutgers!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Blitter Speed(?)
Message-ID: <15489@cbmvax.commodore.com>
Date: 31 Oct 90 17:00:57 GMT
References: <1990Oct24.182854.4530@idt.unit.no>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 68

In article <1990Oct24.182854.4530@idt.unit.no> daglem@solan6.solan.unit.no (Dag Lem) writes:
>In article <15343@cbmvax.commodore.com> you write:

>>There is NEVER one simple answer.

>What IS the not so simple answer, then? 

Some day, you'll know.  Not today.

>Don't tell me Commodore doesn't look upon the custom chips speed as a problem.

Commodore looks upon total system performance as either adequate or inadequate
for a particular job.  For the supported resolutions and things being done,
the Amiga graphics display subsystem is more than plenty fast.

>I certainly do. 

You probably spend too much time either reading spec sheets or in an arcade.
Certainly additional speed is A Very Good Thing, but you should realize that
in memory access, video display, and hard disk, the Amiga 3000 is as fast or
faster than just about every other 25MHz PC on the market.

>I didn't mean to flame Commodore (or you) in my article, I just think it's 
>kind of stupid to have a custom graphics chip that performs worse than a 
>general purpose CPU (68030). 

Most other PCs on the market have no graphics chip at all.  The only other
one I know of with a graphics Coprocessor available is the Mac -- for $2000,
in addition to the cost of a NuBus based Mac II, you can have a card with a
graphics accelerator (in this case, a general purpose CPU, the AMD29000)
that's faster than the host processor.  If you don't get that, the 68030's
access to a NuBus based video display device is SLOWER than the A3000's 68030
access to Chip RAM.  And forget about VGA; the average CPU to VGA memory
access is in the 10-100 wait state range, and that's only an 8 bit access
(even so-called 16 bit VGA cards tend to access video memory 8 bits at a
time, the "16 bit" is mainly just "AT" vs. "XT" bus speed).

And the 3000 does have the blitter; while you may be able to do things faster 
on the 68030 than the blitter, you can't possibly do things faster than blitter 
and 68030 running in parallel on a comparable 68030 system with no blitter.  
In other words, some graphics support is better than no graphics support.

>Well that's my opinion... I LOVE graphics animations, 

You're just spoiled.  You don't get good realtime animation on most PC level
systems.

>and I want mine to be FAST. I'd just like the Amiga to blow away the 
>competition completely, OK? :-) Well I guess people would buy Macs and other
>inferior hardware/software combinations anyway. Shame on them!

People often buy a computer that does [a] what they expect a computer to do
and [b] what they need a computer to do.  If you don't expect a computer to
run animations in real time, you don't get disappointed doing animation on
a VGA based PC.  Until you see something better.

Incidently, most of the speed you get out of ANIM files is CPU based, not
blitter based.  ANIMs tend to load into Fast memory, being decompressed into
Chip by the CPU to a double buffered display to give you nice, clean looking
animation.  It's possible to do some of the same kind of animation on a Mac.
The blitter speed is what's responsible for things moving within chip memory,
like the speed of your window moving, menus dropping, or bobs dashing about
in a video game.

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	Standing on the shoulders of giants leaves me cold	-REM