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From: c60c-4gj@web-2e.berkeley.edu (Calvin Cheng)
Newsgroups: comp.sys.apple2
Subject: Re: New Apple II generation
Message-ID: <1990Dec15.164433.7812@agate.berkeley.edu>
Date: 15 Dec 90 16:44:33 GMT
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In article <2493@unsvax.NEVADA.EDU> alfter@uns-helios.nevada.edu (SCOTT ALFTER) writes:
>
>Clock speed is irrelevant, especially when you consider that the Amiga
>has a million coprocessors while the Mac does almost everything with
>just a 68030/68882 combination.
>
>Isn't the desktop supposed to eat up about 40% of available processor
>power in the Mac?
>
The Mac IIfx has a peak Dhrystone rating of about 12000-15000/s compared to
about 7000-8000 for the 25Mhz A3000.  It also comes with an array of IOP
(10Mhz 65C02s for serial I/O, disk I/O, SCSI I/O with DMA although these are
only taken full advantage of in A/Ux or System 8.0??)  For that matter, it is
about 2.5 to 3 times the speed of a 25Mhz IIci and about 3 to 4 times as
fast as a 16Mhz SE/30 and 10 to 15 times as fast as an SE.  So it is definitely
a beast.  As far as comparison with MS-DOS machines are concerned though,
it's only up to the level of 25Mhz 386 systems (it seems 33Mhz ones are faster)
while the A3000 has been rated to be comparable to 20MHz systems.

Desktop processing speed doesnt take up a great deal of time. Most of the
time the CPU is involved in either performing the long and hard computations
or just waiting for input.  The main effect of a faster processor is that
it helps in screen updates (ie scrolling, redrawing) in response to user
events.  And this is why Windows-based systems are perceived to be slow
(even on 386s) even though they easily chew up the comparable Macs when
performing other operations.

Even 8-bit video on a IIfx is faster than 1-bit video on a IIci.  When u
top it up with Apple's AMD29000-based graphics accelerator, even 24-bit
video looks piece of cake.  But bare in mind that the only real thing that
get speeded up is the screen response time rather than the internal throughput
which is still very much dependent on the CPU hardware.
By the way, screen size has little to do with video speed since normally
the same number of bits are updated regardless of desktop size.  The screen
depth doesnt count up heavily in draw operations too because the number of
bits drawn is normally relatively low (except for say scroll operations).

Lastly, bear in mind that the A3000's coprocessors are not truly geared for
a full-windowing system.  Many of the features can only be activated on a
desktop-wide basis.  They are only truly effective for games that take over
the whole desktop

I'm not trying to point out the deficiencies of the A3000.  I think it's a
wonderful machine esp at about half the price of a IIfx (but not so attractive
now that u can get a NeXTStation for about the same amount).  Each machine
has its own virtue.  I'm seriously considering a NeXT as my NEXT machine.  But
the power of a IIfx is essential for some serious DTP jobs while Amiga users
may want to maintain a kind of Amiga compatibility.

+-----------------------------------------------------------------------+
| Calvin Cheng                                                          |
| calvinc@ocf.berkeley                    The Best is Yet to Be!        |
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